Mustafar

Mustafar was a planet within the eponymous system of the Atravis sector, in the Outer Rim Territories. It was a small world situated in grid square L-19 of the Standard Galactic Grid, and it lay on the Tosste Spur trade route, off the Rimma Trade Route. A part of the Western Reaches, Mustafar was located 53,000 light-years from the galaxy's Core.

With an overlapping orbit, Mustafar was the third orbit of its system around the primary star Priate, completing a full rotation every 36 standard hours and a revolution around its sun every 412 local days, the equivalent of 618 standard days. It had a diameter of 4,200 kilometers, or 2,610 miles, and was a terrestrial world classed as a wasteland during the Imperial Era.

Nourished by the power of the Bright Star artifact, it was once a temperate and lush garden world that thrived with lifeforms that inhabited forests. Millennia before the Imperial Era, Mustafar became an unstable volcanic world with underground caves and lava constituting 35% of its surface, taking the form of lava seas, rivers, and pits interspersed with glens, molten rock plains, as well as obsidian mountain ranges and shores. Few areas were temperate enough to sustain life, and only a few landmasses were not fractured by tectonic disruption and magma flows; allowing lifeforms to evolve deep underground.

The tortured planet was powerful in the dark side of the Force, and, along with valuable mineral allotropes that surfaced from the planet core as well as its obscurity to the wider galaxy, attracted various off-world interests that exploited the molten planet. Mustafar remained a fiery world until the destruction of the Bright Star, at which point the planet was allowed to regrow. Such different states of the world led some to believe that spiritual forces were the catalysts to the changes in Mustafar's nature.

Deep underground, Mustafar contained lava lakes from which fumes drifted up to surface-level facilities; such fumes played tricks with the minds of organics who inhaled it, giving rise to what Lellis referred to as "shadows of the mind"—visions of fears and doubts that could manifest as ghosts of the past. Lava fumes were most potent around the vicinity of the Klegger Corp Mining Facility, and sustained exposure to it drove an individual insane. Repulsor vents were thus installed at the Mining Complex to prevent such toxic fumes from rising to indoor facilities and being inhaled by those within.

Mustafar was twinned with the gas giant Jestefad, which it closely orbited, being constantly pulled by its gravitational force; Mustafar was nearly captured by the larger world as its moon, an event that was only prevented by the counterbalancing gravitational pull from the more remote gas giant Lefrani. Mustafar nevertheless possessed a standard gravity. The influence of the massive magnetic field of Mustafar's larger twin, however, resulted in its hellish volcanic landscape, as the power of Jestefad's gravitational force caused massive tidal disruption that heated Mustafar's interior.

Along with being engulfed in a constant gravimetric battle, Mustafar housed an unstable core that caused groundquakes powerful enough to split the planet's continents apart, and its split tectonic plates allowed the planet's searing magma to push through to the surface, creating a volcanic hot spot visible as a bright red cluster from space.

While great portions of the planet were always in motion, one of the few constant features was the central volcano. Lava poured out of the spot at nearly 100,000 liters per second and pooled at the giant volcano's base. To the north was a region named the Burning Plains, which boasted heavy volcanic activity. Another region earned its nickname, the Smoking Forest, as smoke spewed from its tree-like rock chimneys. Mustafar's Berken's Flow was the largest lavafall in the galaxy, while Tulrus Island—which shared its name with the tulrus creature—was surrounded by tall mountains.

The young world's instability churned magma that carried ores with unique and valuable minerals to its surface, attracting business interests from various galactic mining conglomerates such as the Mining Guild to exploit the mineral wealth of the otherwise untouched world. Mining facilities were set up for minerals and metal ore, including dolovite, gold, and mirkanite.

The searing magma that bubbled beneath the surface flooded the planet, covering it in oceans and rivers of lava. Geothermal energy was the main power source of the Techno Union's mining complex on the planet, and the lava flows that coated the rocky terrain left behind traces of flood basalt. At 800°C (1500°F), Mustafar's lava, while still very hot, had a lower temperature than that found on other worlds due to unusual mineral allotropes that were molten at lower temperatures. Nevertheless, patches of Mustafar began to cool in the decades leading up to 35 ABY.

Mustafar's atmosphere was influenced by the breath of its volcanoes and Jestefad's massive magnetic field. Along with cyclonic-force updrafts and thermal currents, titanic lightning storms made up the planet's unfriendly skies. Turbulent and ash-laden, the atmosphere was also hot and chemical, consisting of thick clouds of black smoke and allowing for choking ash to fall like rain. Lava processing operations created toxic gas by-products, and a noxious air cast the world in a hazy fog. Thus, Mustafar was classified as a world with a Type II atmosphere, wherein the usage of a breath mask was recommended.

The frequent electromagnetic interference and lightning storms in the atmosphere respectively led to signal loss and noise, although the effects of Mustafar's hectic skies could be reduced through the use of dedicated dampers. The planet's magnetic field interfered with sensors installed on the surface, and electromagnetic interference also posed a significant risk for off-world arrivals and departures. Those caught in one such storm without the assistance of specially shielded surface-level landing equipment—which included energy-shielded landing pads and guidance and tractor beams—found, at best, their starship's scanners rendered useless and navigational equipment and control systems interfered with. In certain cases, a ship was torn apart as Mustafar was by Lefrani and Jestefad. Ships were additionally threatened by Mustafar's intense heat and incendiary ash, although any damage could be prevented should a vessel be equipped with sufficiently powerful energy shields.

Despite the hellish environment after its devestation, Mustafar was teeming with life, a home to fragile but determined organisms all connected through the Force energy field. All surviving lifeforms had evolved deep underground, in the few areas that remained temperate and with landmasses were not fractured: in the solid rock betwixt lava flows lived mammalian, reptillian, and insect species, although reptillian and insectoid lifeforms proved to be the most successful survivors, aggressive in nature and with tough skin or carapaces. The extremophile creatures of the planet had adapted to Mustafar's desolation and become indomitable. The sentient Mustafarians were insectoid, and were forced to live largely underground in Mustafar's north and near the equator.

Much like the planet itself, some of the creatures found on Mustafar were especially deadly. Highly aggressive creatures posed a significant hazard on the planet due to its scarce resources. The planet's apex predator was the scorpion-like Sher Kar, which lived deep in the nesting grounds of their tulrus prey. The fearsome darkghast, similar in some respects to the rancors of the planet Dathomir, was a multi-limbed carnivore that dwelled beneath the world's rocky surface.

The reptillian blistmok hunted in packs and were capable of pursuing their prey for days. The insectoid xandanks were well protected by their armor and hunted in packs as well. Tough, semi-sentient creatures named roggwarts hunted the planet's tunnels and lava tubes in search of xandanks, as well as for giant, human-eating lava eels. Despite the danger of roggwarts, they could be domesticated with the proper training and were imported to Mustafar to work in the planet's mines.

By 3 BBY, a roggwart named Kongo the Disembowler was employed to keep the dolovite mine tunnels free of xandanks and lava eels. Kongo was reputedly the last of his kind by between 0 and 1 ABY, although it may have been said in an effort to make the roggwart seem more mysterious and exotic.

The large insectoids known as lava fleas had developed a tough exoskeleton that protected them from the world's fiery devastation. They lived largely underground and ate away at the planet's crust, feeding on the surface's rich minerals, rocks, and dirt and were commonly used as domesticated mounts by the sentient Mustafarians. Lava fleas and Mustafarians thus had a close connection and were the only species that thrived on Mustafar.

The large, lumbering egg-laying tulrus had sharp tusks and bad temper, while the small jundak parasite attached itself to a host and eventually bursted out, killing the host and developing into a large adult. Lizard-crows occupied Mustafar's lava fields; these creatures were often scared away by what the Mustafarians referred to as "molten men." Spark-roaches and rodents called fire rats also called Mustafar their home, the latter of which gnawed on the lava crystals that formed on the planet.

Lava nymphs were winged creatures that inhabited the planet's caverns in hives. Considered to be vermin, the creatures' insides were filled with lava, which they were able to spit out when provoked. Feeding on minerals, hives of kubaza beetles lived near lava flows and were fierce defenders of their nests; starting life as a small larva, the creature developed a defense mechanism by the time it reached adulthood that allowed it to warn its brood by exploding. Burrowing quadrupeds known as krishels inhabited Mustafar's labyrinthine caverns and tunnels. Those strong, hardshelled creatures were hunted by the Mustafarians.

Although the lush vegetation that once covered the planet eventually disappeared beneath fire and ash, Mustafar was not devoid of fungal and vegetal life. Hidden away from the world's searing lava rivers, kahel cave fungi grew underground. These organisms were deeply symbolic to the native Mustafarians and served as the inspiration for their mushroom-like architecture. Following the destruction of the Aeon Engine during the Imperial Era, the muggy marshland of Corvax Fen developed near Fortress Vader, and life began to slowly creep back once again. By 35 ABY, barren irontrees stood in the few places where fertile soil existed, including the fen.

In its ancient past, Mustafar was a lush and forested terrestrial planet, thriving with life through the Bright Star, the native Mustafarians' most sacred artifact that nourished the small garden world. It housed an enclave of the Jedi, servants of the Force, that drew attention from the Jedi's enemy, the Sith. After a thousand years of skirmishes between the two groups, they came to a titanic battle in the Mustafar system that brought havoc to Jestefad, Lefrani, and Mustafar five thousand years before the Imperial Era.

Ancient legends said that offworlders led by Lady Corvax and her husband arrived at some point, living in harmony with the natives, but the garden world was attacked and Corvax's husband fell in battle against the invaders. Unable to let go of her love, Corvax stole the Mustafarians' Bright Star in her pursuit of immortality, having thought it had the power to resurrect her husband from death. Corvax created the Aeon Engine and encased the artifact within, although her actions ultimately resulted in the devastation of the planet; energies ruptured from the Bright Star, pushing Mustafar out of its original orbit. Other legends claimed that due to a cataclysmic struggle between the Sith and the Jedi, the orbit of the gas giant Lefrani was also shifted, and Mustafar entered an unusual and gravitationally crushing alignment between it and Jestefad's magnetic fields.

With the devastation of Mustafar, the world's new, precarious orbit rendered it a volcanic wasteland as both gas giants pulled on tiny Mustafar, heating its interior in their attempts to claim Mustafar as their moon. The crust of the smaller world was also torn apart, allowing the flow of lava toward the planet surface. Very few species survived the cataclysm, with the homes of nearly all native species being destroyed. The remaining life-forms evolved deep underground, in the few areas temperate and stable enough to support life, and developed short, tough bodies to endure the superheated clime, and the Mustafarians were forced to areas in Mustafar's north and near the equator. There, they adapted and evolved to the new realities of life on Mustafar.

These events passed into legend, attracting Sith who were looking for the secrets of eternal life. Eventually, a Sith shrine was built on the world's Gahenn Plains as part of a Sith temple, at the site of Lady Corvax's underground castle. The Jedi had been forced to abandone their enclave on Mustafar following its devestation, and the world was used by a Force organization named the Blackguard. At some point, a Jedi and another individual fought a Sher Kar on Mustafar.

Over three hundred years before the Clone Wars, the Techno Union came to own the planet and charged the Mustafarians rent. The Union built giant mining stations across Mustafar, where much of the ore extraction was done through heavily automated electromagnetic processes, and they led to valuable elements congealing as scum on top of the lava. The corporation thus provided the Mustafarians with tools to mine mineral allotropes for them, labor which served to pay their rent. Mixed with workers of a great variety of other species, Mustafarian miners lived in simple residences at dedicated though run-down mining towns, and aside from riding lava fleas, they were helped by Techno Union technology.

The Trade Union supplied Mustafarians with technology such as the Baktoid repulsorlift-powered platforms, lava-processing centrifuges, electrorefining droids, and the DLC-13 mining droid to collect mineral-rich lava spewing from Mustafar's heated interior, with the ore extraction droid also seeing use. Over the centuries, Mustafarians became wary of technology that failed under the intense heat of their world and which had an inadequate melting point, having been witness to mechanical breakdowns. Such was the case for speeders, including the heavy-duty UH-XH, which were generally left to be operated by droids. Nevertheless, by the Clone Wars' end, Mustafar had served as a literal gold mine for the Techno Union for almost three hundred standard-years.

Damask Holdings also established a presence on Mustafar through a base. Although Mustafar came to be known primarily for its mining activities, those desperate offworlders and law-evaders who were undeterred by the world's harsh conditions were drawn to it as a result of the obscure world's sparse population. Mustafar was also ideal for hiding or disposing items in secret. On the world Felucia, an individual romantically involved with the Jedi Padawan Qui-Gon Jinn in 60 BBY gifted him a rare Mustafar fire diamond. In 40 BBY, jewel thieves Pax Maripher and Rahara Wick discussed whether they should collect Mustafar fire diamonds, with Wick dreading the notion of doing so, before deciding to travel to the planet Pijal for kyber crystals instead.

During the Clone Wars, the Mustafarians aligned themselves with the Confederacy of Independent Systems. However, they were not fanatically committed to the cause, having only joined to secure themselves Separatist contracts, and life continued much as it had before. With members of the Jedi Order, the galaxy's guardians of peace and justice, focused on defeating the Separatists, law enforcement found itself in a declining state, especially in the infrequently patrolled Outer Rim. Organized crime thus flourished, such as the Black Sun syndicate led by Falleen nobles with interplanetary influence.

The Falleen operated clandestinely, establishing elusive holdings on Mustafar and headquartering themselves in a well-defended fortress, where they regularly met and found the surrounding lava useful for the disposal of evidence. The native Mustafarians cared little for Black Sun, since most of their operations took place elsewhere in the galaxy. Hidden away from prying eyes, the Techno Union also produced battle droids behind their Mustafarian mining operations, situated within the same mountain as their Klegger Corp Mining Facility, at the time of the Clone Wars.

Aside from skirmishes and lesser operations, fighting largely passed Mustafar by during the Clone Wars, resulting in the planet retaining a reputation as a remote astronomical object that individuals usually only stopped on to refuel. Nevertheless, the planet bore witness to a plot to kidnap Force-sensitive children by bounty hunter Cad Bane, who was under the employ of the Dark Lord of the Sith Darth Sidious. Traveling on his starfighter, the Xanadu Blood, Bane deposited the children at Sidious' secret facility, where the Sith planned to create an army of spies strong in the Force. Upon reading through the captured Xanadu Bloods fuel logs, Jedi Padawan Ahsoka Tano reasoned the world could be where Bane deposited the kidnapped children, so she and her mentor, Jedi Knight Anakin Skywalker, traveled to Mustafar and rescued the children, and the facility was destroyed by Sidious' nanny droids on his orders, ensuring the loss of any evidence of the plot's mastermind. By the time of the war, Darth Sidious was familiar with the existence of the Sith temple at the Gahenn Plains.

In 19 BBY, renegade Sith Lord Maul, his apprentice Savage Opress, and Pre Vizsla, the leader of the Mandalorian terrorist organization Death Watch, traveled to the Black Sun fortress with the intention of recruiting them to their newly founded criminal empire, the Shadow Collective. The Captain of the Guard, Ziton Moj, greeted them upon their arrival and led them to the Black Sun's leaders, headed by the Falleen Xomit Grunseit, who hailed from Mustafar. After negotiations with the leaders went sour, Savage beheaded all of them with his lightsaber. Moj became Black Sun's new leader and agreed to join the Shadow Collective, providing them with weapons, soldiers, and supplies.

When Quinlan Vos was sent undercover as a bounty hunter to work alongside Dooku's former apprentice, Asajj Ventress, the pair was hired by the Pyke Syndicate to retrieve Marg Krim's wife, Tezzka Krim, and their children, Vram and Laalee, who were kidnapped by Black Sun and brought to their base on Mustafar in order to bribe the Pykes into joining Maul's Shadow Collective. The two traveled to Mustafar in Ventress' ship, the Banshee, and entered Zitontown, where they sought to gather information at the lone bar in the town, named The Last Resort. Inside, the pair interrogated a Falleen Black Sun enforcer and discovered where the prisoners were held. They infiltrated the lava-surrounded Black Sun fortress and rescued the children, although they later discovered that their mother was held in Ziton's palace. After the pair freed Tezzka, Moj had mobilized his forces for departure from Mustafar to attack the Pykes on the planet Oba Diah.

As the war's end drew nearer, Darth Sidious instructed the Separatist Council to retreat to their facility on Mustafar, and they gathered at the Techno Union's Klegger Corp Mining Facility under the leadership of Viceroy Nute Gunray. Soon afterward, the Jedi Anakin Skywalker made a pact with Sidious, becoming his new Sith apprentice, Darth Vader; the Jedi-turned-Sith was desperately hoping to gain the power to save his lover and wife, Republic Senator Padmé Amidala, from dying. Darth Vader's first mission was to eliminate Separatist leaders on Mustafar.

Traveling from the Republic capital world of Coruscant in his interceptor alongside his droid R2-D2, Vader arrived at the Separatist facility's war room and promptly slaughtered the Separatist Council and their guards, bathing in the power of the dark side. At his master's command, Vader further transmitted the order to deactivate the Separatist Droid Army immediately, effectively ending the Clone Wars. At the same time, the Republic's clone army was ordered to kill all Jedi, and Darth Sidious took the opportunity to found the Galactic Empire with himself as the Emperor, fulfilling the Sith Grand Plan with his aim to seize control of the galaxy.

A rumor spread over the fire plains of Mustafar that a Jedi Knight—a reputed protector of light, guardian of peace and life, and a hero of the Republic—had been spotted at the Mining Complex. The Mustafarian boy Kakan hoped to exact his dream of meeting a Jedi, and so approached the fallen Anakin Skywalker. The Sith Lord was viewing the eclipse of Mustafar's sun by Lefrani at the complex's balcony, just as Vader's massacre of the Separatists eclipsed the light of the Force within him.

However, Kakan saw that the figure was not the Jedi he expected. The fallen Jedi's eyes radiated such anger and hate that Kakan was compelled to run away, escaping to the complex's foundry. Kakan found the miner Lellis, who operated the facility's repulsor vents, releasing fumes from the depths of Mustafar that gave one illusions when inhaled. The potent fumes overwhelmed Vader with his fears, and Kakan and Lellis took advantage of his distraction to escape. However, as fear took hold of the boy as well, the two Mustafarians fell into a lava lake, but they were saved by a burst of Force energy released by Darth Vader in a bout of anger.

Padmé Amidala had been rushing to Mustafar in the hope of saving her husband from falling further to the dark side. She arrived on the volcanic world shortly after the slaughter of the Separatist leaders, and Vader met her embrace at the Techno Union facility. Her pleas fell on deaf ears, however, when Vader spotted his former Jedi Master, Obi-Wan Kenobi, emerging from Amidala's ship. In his anger, Vader incorrectly assumed that her lover had betrayed him to Kenobi and strangled her via the Force; Amidala thus realized that Anakin Skywalker had been consumed by his lust for power and was truly corrupted by the dark side.

Darth Vader then gave his old master and former friend an ultimatum: either he was with him or against him. Plagued by self-doubt and his inability to let go of his assumptions, Vader attempted to murder Kenobi. As the two engaged in a lightsaber duel, Vader bathed the remnants of his Jedi self in the dark side that echoed from Mustafar's Sith sanctum, and amid the chaos, the shields protecting the mining facility were shut down. Parts of the building as well as the Lapiz Cutter—the late Nute Gunray's personal shuttle—were destroyed.

Forced to fight across the lava streams, Vader was fueled by hatred and, in his hubris, attacked without regard to his own limitations, and fell victim to Kenobi's blade beside a lava river. As the Sith Lord lost himself to the dark side's corruption, his remaining limbs were severed and his entire body was incinerated by Mustafar's lava.

The fallen Jedi's lightsaber was then taken by Kenobi, who left him to die on the sands of the river bank and took Amidala to a base on the asteroid field Polis Massa in order for her to give birth to her and Anakin Skywalker's children—the twins Luke and Leia. Although charred and broken, Vader was recovered by Sidious, and he was brought back to Coruscant to be rebuilt with cybernetics at the Grand Republic Medical Facility with the technology of the acclaimed scientist Cylo, becoming encased in a suit of terrifying black armor.

Despite his survival, the events of Mustafar haunted Darth Vader throughout the age of the Empire, affecting the Sith's performance as the Emperor's primary enforcer. Seldomly, stories circulated amongst Mustafarians of a great Jedi duel on their world, although no evidence was given for such tales. Mustafarians nonetheless had knowledge of the former Jedi who slaughtered the Separatist leaders and nearly killed the boy Kakan and the miner Lellis, and whilst some thought that the fallen Jedi Knight was gone, others thought that he still remained in the mists of Mustafar. Years later, Lellis realized that Darth Vader was the very same fallen Jedi Knight, overshadowing his people since the rise of the Empire.

Over a year after the battle against his former friend on Mustafar, in 18 BBY, the memory of Darth Vader burning on the volcanic slopes of Mustafar resurfaced in Obi-Wan Kenobi's thoughts along with other past happenings. Despite the pain inflicted by the memories, Kenobi willed himself to let go of his traumatic past and focus on his present—his mission to watch over Luke, the son of Anakin Skywalker.

A short time after his loss to Kenobi, in 19 BBY, Vader returned to Mustafar under instructions from Darth Sidious. Vader was to bleed a kyber crystal he had obtained from the Jedi Master Kirak Infil'a, who he killed, in order to gain a crimson crystal for his new Sith lightsaber. He traveled to the dark side cave that contained the shrine erected by the ancient Sith and poured all of his pain and anger into the crystal, making it sing a hymn of darkness. With this new weapon, Vader returned to Coruscant by his master's side, another step closer, Sidious believed, to becoming a true servant of darkness.

Although Sidious had lost his original facility during the Clone Wars, he soon built additional installations on Mustafar where he continued to abduct Force-sensitive infants. Over time, he manipulated these children and molded them into new members of the Inquisitorius, a group of dark side agents trained by Darth Vader and initially made up of former Jedi, including the Grand Inquisitor, since soon after the Empire's founding. Sidious stole the childhoods away from these individuals, turning them into hunters of the Jedi they may have otherwise become.

In 14 BBY, Vader captured the former Jedi Chief Librarian Jocasta Nu, a survivor of the Jedi Purge at the end of the Clone Wars, and obtained a memory crystal given to Nu by Jedi seekers who identified potential Jedi Initiates from throughout the galaxy—it listed the names and locations of many Force-sensitives, including one Nik Lowe on Mustafar. Wary that the Emperor could replace him with another Force user, Vader murdered Nu and destroyed the memory crystal.

After the Chiss Mitth'raw'nuruodo "Thrawn" came into contact with the Empire in 14 BBY, having been attacked by a talented trio of cadets when he was studying at Coruscant's prestigious Royal Imperial Academy, Thrawn recommended to Commandant Deenlark that his assailants be transferred away. When a derisive Deenlark asked if they should be transferred to Mustafar as punishment, Thrawn suggested that the three train instead as starfighter pilots at the elite Skystrike Academy on the world Montross.

Fascinated by the power he tapped into in the Sith cave on Mustafar, and associating the world with his rebirth and personal connection to the dark side, Vader requested that the world be given to him by his master in 14 BBY, believing that the planet held the key to seeing the deceased Padmé Amidala once again. Gifted with the late Amidala's royal starship, the mask of the ancient Sith heretic artisan Darth Momin, and a team of top Imperial architects, Vader departed Coruscant for his new home. The Sith Lord entered the planet's violent atmosphere unshielded, causing severe damage to his vessel and casting a streak of fire across the smokey sky. His entry was witnessed by the Mustafarian Father Kkkt, who warned his clanmate Zzzs that the fireball was an omen of events to come.

Landing near the Sith cave, Vader meditated in its dark walls, leaving the Emperor's architects, Colonel Alva Brenne and Lieutenant Roggo, to draw up plans for a personal base Vader could inhabit. Brenne scouted the planet's terrain, believing that, although Vader was seemingly impossible to satisfy, she could manage to design a home suitable for the Dark Lord. Unbeknownst to the architects, the mask that Sidious had gifted Vader was possessed by Darth Momin's spirit; it took control of Roggo, using his body to kill Brenne and create its own designs for the base.

Vader confronted the spirit, killing its host body and demanding that it gives him answers. The spirit introduced itself as Momin and offered to help Vader construct a fortress that would harness the energies of the dark side locus below the cave to open a door into the Force itself; through and beyond the limitations of time and space. Upon being attacked by Father Kkkt's scout party, Vader abducted the Mustafarian Sssp to serve as Momin's new body and let Rrrn flee. The two Sith Lords subsequently took command of a vast Imperial construction force on the Gahenn Plains and began their work on what would become Fortress Vader.

Vader would exercise control over the entire Mustafar system. Around this time, the Inquisitorius' headquarters were moved from Coruscant to the moon Nur in the Mustafar system, keeping close to Vader and his planet. A base but also a clandestine place of incarceration and torture for Jedi, the Fortress Inquisitorius tower was built to complement the castle on Mustafar using black stone from the world in 14 BBY.

The construction of Vader's fortress was not a simple task. Over the course of eight attempts with at least five separate designs, Momin struggled to find the perfect structure that could correctly channel the dark side. The energy Vader exerted while attempting to open a rift in the locus caused electromagnetic storms to rage across the planet, throwing the world's creatures into a frenzy and casting the Mustafarian people into disarray—the natives found that their "lifefires" barely burned. As an Imperial-class Star Destroyer loomed overhead, the new Imperial garrison managed to defend the site against small uprisings by the Mustafarians and lava fleas. Father Kkkt, realizing the danger Vader posed to his world, rallied the clanholds across Mustafar prepared to mount an attack on the Imperial intruders.

Upon the completion of Momin's ninth design in 12 BBY, Vader was finally able to reach through the Force and open a pathway into time, but he was interrupted in his moment of triumph by Kkkt and his forces. With the Dark Lord distracted, Momin entered the portal and claimed his original body, betraying Vader. Kkkt's army had initial success in pushing back Captain Junus' garrison, attacking the Imperials, whom they outnumbered by ten to one, with surprise tactics. Vader, however, soon arrived on the front lines and rallied his magma troopers to double their efforts. Recognizing Vader as the Imperial leader, Kkkt led the Mustafarians in a powerful usage of the Force, drowning the enemy forces in a vast flood of lava. With his army wiped out, Vader retreated into the fortress, summoning his own massive force of energy to destroy the Mustafarian attackers.

Returning to the inner sanctum, Vader confronted Momin, who mocked the cyborg Sith for his failures in service to the dark side. Using Momin's hubris against him, Vader crushed and killed the resurrected artist. With no one to stop him, he entered the portal, encountering visions of his past and future, including his beloved wife, Padmé Amidala. Upon witnessing what her husband had become, however, the vision of Amidala ran from Vader, choosing to plunge into an abyss. A beam of light containing a figure that he did not know was his son then overwhelmed Vader. Frustrated with the dark visions, Vader retreated and crushed the altar in the Sith cave, destroying the portal and accepting that the truth he encountered was exactly what he needed. The Dark Lord later returned Momin's mask to Sidious; both master and apprentice frequented Mustafar, using it to focus their meditation on the power of the dark side of the Force.

Black Sun departed Mustafar to a lower profile world after the Empire had established a garrison there. The Techno Union similarly abandoned their operations, and their remaining resources were taken over by the Mining Guild, but they struggled to profit on Mustafar due to the strict travel restrictions imposed by the Empire. The Empire replenished their garrison and maintained secret facilities on Mustafar where survivors of the Jedi Purge were interrogated and executed, although the lava planet remained publicly notable only for its mining operations. Rumor had it that Darth Vader carried out these interrogations, torturing the Jedi for any useful information before their execution. As the world remained under heavy Imperial guard, mining operations there eventually ceased.

In 11 BBY, the term "Mustafarian Special" was used by smuggler Lando Calrissian and his first mate, L3-37, to refer to a starfighter maneuver that involved great speed and surprise, and which ensured at least one side of a starship confrontation "end[ed] badly." L3-37 explained that the tactic was named such in reference to the eponymous lava world's fiery nature.

Following Kkkt's failed attack and the completion of Fortress Vader—according to a story told years later by the Mustafarian Lellis—Darth Vader sought candidates for a servant who would attend to his needs, searching for months until a human named Vaneé came into his service around 12 BBY. During Vader's search, an Imperial officer was sent from Imperial Command to Mustafar by Moff Seward, and was tasked with handling an outbreak of insanity amongst Imperial lava troopers assigned to Fortress Vader. On Mustafar, the inspector found that the troopers had inhaled toxic fumes from the planet's depths that gave one illusions of fears and doubts, and he entered Vader's castle to speak with Darth Vader himself with the intention of resolving the matter. However, Vader, bathing in his bacta tank, instead forced the officer to inhale the fumes and confront his fears by holding him in place via the Force, refusing to let the human go. Face with the illusions caused by the Mustafarian fumes, the inspector denied their existence and began to laugh, laughing for days until he took advice from the voices by his head and became Vader's servant, named Vaneé.

Eventually, years before the Battle of Endor of 4 ABY, the lava fumes leaking into Vader's castle were blocked off. During the early days of Vader's reign over the planet, Vaneé witnessed the efforts of a second force of Mustafarians to push the Sith away from their homeworld. The group, led by Criakan, desired vengeance for their slaughtered kin and stormed the fortress in a surprise attack. Surrounding Vaneé, Criakan and his forces intended to show no mercy to the Imperials, but were shown the same respect by Lord Vader, who cut them all down before they could burn down the castle.

Sometime later, during a visit from the Emperor's adviser Rersey, a third attack on Fortress Vader was undertaken by Clan Rrrt's Mother Sssl, a Mustafarian priestess who could force her will upon others by subjecting them to a mind-altering plague. Sssl's forces soon overwhelmed the Imperials, infecting Vader's soldiers and turning them against the Sith. Although Sssl had only intended to scare off the invaders, her plans changed when the Dark Lord himself was seemingly infected. In reality, Vader's mechanical body was immune to the plague, allowing him to feign subservience and draw the priestess out. Using a mind trick, Vader forced Sssl to order her own forces to drag her into the lava—a scene that made Rersey lose his sanity. Vaneé praised his master and noted that the Mustafarians would fear Vader's name in the future.

In 9 BBY, Darth Vader conferred from Fortress Vader with the Third Sister via hologram regarding their hunt for Obi-Wan Kenobi following a failed attempt to capture him. Kenobi later infiltrated Fortress Inquisitorius on the nearby moon Nur using intelligence from the Hidden Path rebels, who further found that Vader was not in the Mustafar system at the time, instead being aboard his vessel elsewhere. The hunt was ultimately a failure, and from his castle, Vader was instructed by Darth Sidious via hologram to abandon his obsession with Kenobi.

In 4 BBY, the Jedi Kanan Jarrus, a leader of the Spectres rebel cell, was detained aboard Grand Moff Wilhuff Tarkin's flagship, the Imperial Star Destroyer Sovereign, in Mustafar's orbit. Escorted by a fleet of three other Star Destroyers and support vessels, the Sovereign bore witness to the Grand Inquisitor's interrogation of Jarrus. When Hera Syndulla led the Spectres in rescuing the captive Jedi, the Sovereign was destroyed during a duel between him and the Grand Inquisitor—the latter's lightsaber was bisected and fell into the ship's reactor, which exploded and sent the vessel falling toward the lava fields below.

With the aid of Phoenix Cell, a resistance group affiliated with a growing network of rebels formed by Senators Bail Organa and Mon Mothma, the Spectres successfully extracted their Jedi leader and joined the larger Phoenix Cell. While the skirmish over Mustafar became one of the earliest rebel victories in the Galactic Civil War against the Empire, Mothma wrote in The Rebel Files documents that it was but a short-term success, considering that the rebels had revealed their naval capacity to the Empire.

Having become a part of Bail Organa's rebel network, Kanan Jarrus and his pupil, Ezra Bridger, began working with the former Jedi Ahsoka Tano. In 3 BBY, Tano reported to Kanan Jarrus her investigation on the Sith Lord who attacked them over the planet Lothal shortly prior—unbeknownst to them, he was Darth Vader and formerly the Jedi Anakin Skywalker, who instructed Tano. She had been monitoring transmissions from Mustafar, and while information on the Sith Lord remained elusive, she had gathered more intelligence on the Empire's Inquisitors. The former Jedi decoded two sets of coordinates from the Mustafar transmissions, and she and the Spectres investigated the world Takobo, where they uncovered the Inquisitors' plot to kidnap Force-sensitive infants. Tano recalled that it was similar to the kidnapping attempt that she and her master had foiled on Mustafar during the Clone Wars.

In 1 BBY, based on intelligence about the Empire's operations on Mustafar, a small rebel force was sent by Captain Cassian Andor to infiltrate an Imperial base located near Vader's castle and steal a vital artifact. Upon infiltrating the base, the rebels discovered the artifact was a proto-saber, a precursor to the lightsaber, and escaped with information about the ancient weapon despite Vader's intervention.

In the same year, while Mustafar maintained its reputation as a mining world, a smuggler and ZO-E3 aboard the Windfall were forcefully taken to Mustafar, having been taken out of hyperspace in the Mustafar system by an Interdictor-class Star Destroyer commanded by Admiral Gable Karius. The smuggler and ZO-E3 were held in Vader's castle, where the Sith Lord found that the smuggler was a descendant of Lady Corvax. However, they then escaped below the castle to the underground Corvax Fortress, meeting the Mustafarian Priestess and activating Lady Corvax's droid army to attack the Imperials.

Darth Vader briefly taught the Corvax descendant to harness the power of the Force in order to retrieve the Bright Star artifact, wishing to revive Padmé Amidala with it. The Sith Lord was prevented from doing so by the descendant, who staged an escape from the fortress and destroyed the Bright Star and the Aeon Engine, allowing Mustafar to begin restoring its forested ecosystems. Near Fortress Vader, the fertile soil grounds of a bog named Corvax Fen began developing.

Later still in the year, the Empire completed construction on the Death Star, an orbital battle station capable of destroying a planet. After a rebel attack on a laboratory on the world Eadu threatened to expose the Death Star's capabilities to the galaxy at large, Vader summoned the director of the project, Orson Krennic, to his fortress on Mustafar. Krennic, arriving while Vader was sustained within a bacta tank, was escorted into Fortress Vader's rotunda by Vaneé to await the Dark Lord. Confronting the uneasy director, Vader admonished Krennic for his mistakes, using the Force to choke the aspirational officer when he further requested an audience with the Emperor. With his message relayed, Vader watched Krennic's ship depart for the planet Scarif. Despite Vader's threats, Krennic failed in his endeavors and the Death Star was soon destroyed by the Rebel Alliance. Around the same time, the rebels also destroyed the Empire's Mirkanite Mining Facility on Mustafar.

Later in the war between the Empire and the Rebellion, a crew of rebels led by Commander Lina Graf was attacked by Imperial forces, and their ship, the Auric, was heavily damaged. They were forced to crash-land on Mustafar, a planet that Graf hoped would lead to her crew's salvation. Surrounded by lava, the rebels abandoned their ship and began toward the only structure in sight, Vader's fortress.

They did not make it far before being attacked by Mustafar's exploding beetles. After defeating the beetles and arguing over the best course of action, Graf and her crew were cornered by a squad of Imperial Lava Troopers. Escaping the troopers, the group entered the fortress but soon became separated in its dark halls. Alerted to their presence by his aide Vaneé, Vader confronted the rebels, capturing Lieutenant Thom Hudd and destroying the bodyguard droid XM-G3, although Graf and her remaining crew managed to escape Mustafar. The rebels' successful escape from Vader's castle was remembered by the native Mustafarians by the aftermath of the Empire's collapse.

For the next several weeks, Vaneé kept Hudd locked within the fortress and tortured him, all the while tormenting him with horrific tales from across the galaxy, including the story of Vader's brutal murder of Sssl years prior. The abuse and starvation that Hudd suffered while chained to the Sith servant's torture web was so severe that he lost enough body mass to slip from his shackles and escape his cell. Hudd managed to send a distress signal to the Alliance but was ultimately recaptured and sentenced to death. His execution was stalled by Graf, however, who had returned to Mustafar disguised as an Inquisitor. Although Vaneé saw through her ruse, Graf and Hudd were able to escape and flee the planet with the rest of their crew. Vader, angered at his servant's ineptitude, rigged Vaneé up to the torture web.

The loss of the Death Star served to galvanize resistance across the galaxy, causing trouble for the weakened Empire. In response to the outbreak of rebellion, Vader was met at Fortress Vader by Admiral Kendal Ozzel and General Maximilian Veers. Overlooking Mustafar's lava fields, the trio discussed the proper route to deal with the rising Alliance, although Vader viewed Ozzel's suggestions as nothing more than excuses for incompetency. An interesting point from General Veers, however, persuaded Vader to view the rebels in a new light, prompting him to develop a different plan to cripple the Alliance.

In 3 ABY, Vader attempted to turn his son, Luke Skywalker, to the dark side during a duel over the planet Bespin. After Skywalker fled, Vader temporarily abandoned his duties to the Emperor, embarking on a personal quest that led to the discovery of a rebel cell led by Sabé, the former decoy of Padmé Amidala. Vader allowed the rebels to live, a decision which convinced Sidious that his apprentice was in need of a reminder of his place. The Emperor mutilated Vader on Coruscant, ripping his cybernetic limbs from his body and strangling him as he had done to men like Krennic in the past.

Not finished with his lesson, Sidious took his student back to Mustafar. He had Vader's personal guard of death troopers drag him to the spot where Kenobi had defeated him decades ago, leaving the apprentice to fend for himself. Warned by his master that there would be consequences should he use the Force to save himself, a one-armed Vader crawled along the lava banks and retrieved his fallen lightsaber before slowly making his way to the ruins of the Techno Union installation. Sidious watched from Vader's Lambda-class shuttle as the broken man pulled himself across the sand. Although Mas Amedda, the Emperor's Grand Vizier, warned that the Dark Lord planned to kill his master, Sidious was unconcerned and sent his Sith assassin, Ochi of Bestoon, to turn Vader's anger into pain.

Having reached the Techno Union installation ruins, the very building where he had slaughtered the Separatist Council decades prior, Vader repurposed surrounding Separatist droid parts as his own limbs and confronted Ochi, overpowering the assassin and demanding him to reveal Darth Sidious' plans. As Vader did so, the oracle Eye of Webbish Bog called out to the Sith Lord, who, despite being deprived of his chest box and lightsaber by Ochi, fought his way through hordes of lava nymphs and lava fleas as well as a roggwart to reach the Eye's lava cavern. As Vader did so, he was tested by the Eye and reminded of his inner conflicts between his chosen Sith and Jedi destinies as well as between his personal desire of power and his need for his son. During Vader's journey to the Eye's lair, Sly Moore and a group of death troopers spoke to Ochi, reminding the assassin to abide by the Emperor's directives.

At the end of Vader's trek to the Eye, the latter gave the cyborg a wayfinder and allowed him to leave the cavern to rejoin Ochi. Once outside, Vader made his way to the green Jedi starfighter that he took to Mustafar at the end of the Clone Wars, repairing the ship until Ochi reappeared with the Droid Crush Pirates of Bestoon. Having been promised Vader's cybernetic parts by Ochi, the army of droid pursued the Emperor's enforcer until they found that his parts were no more special than their own. In the midst of a quarrel with Ochi about their deal, the droids were interrupted by Vader, who took down the machines for use in retrofitting his green starfighter and an escape pod, which he locked Ochi in after forcing the assassin to activate his wayfinder. In his determination to find the Emperor's secrets, Vader bound the pod to his starfighter and set off to the wayfinder's coordinates, reaching the vicinity of the Unknown Regions world Exegol via hyperspace.

With Ochi in tow, Vader confronted Sidious on Exegol, an ancient Sith world which housed hundreds of Sidious' secret experiments and weapons. The Emperor reminded his wayward apprentice that he left him weak and broken on Mustafar's burning shores, and asked Vader what he learned from the experience. However, Vader remained rebellious, stating his intention to make his "master" fear him. Despite Vader's efforts, he was overwhelmed by Sidious' power. Terribly pained, Vader, despite having experienced a vision of his son telling him it was his destiny to destroy Sidious, accepted his master's dominance over him before leaving Exegol with him and Ochi.

Later, between 3 ABY and 4 ABY, Lady Qi'ra's criminal syndicate, Crimson Dawn, hired the Knights of Ren to raid Fortress Vader to acquire the Screaming Key artifact—Darth Sidious had placed the key there, but did not know that it unlocked Momin's fabled Fermata Cage, which held power that threatened even the Sith. In her quest to destroy the Sith, Qi'ra had obtained the full layout, access codes, and security details of the fortress and convinced the Knights' leader, Ren, to go ahead with the raid despite initial reluctance from other Knights. Massif had complained that "the job was too hot," Mustafar's surface being a hellscape aside. Nevertheless, Qi'ra promised the Knights glory and the freedom to claim any objects aside from the key.

The group landed their vessel, the Night Buzzard, on the Gahenn Plains and approached the fortress from the south on speeder bikes with their jammers activated; Ren had concluded that the sensors of the Imperial garrison on the building's far side could not detect them given Mustafar's magnetic field. By using the Force to clear a way through the lava shielding the Sith cave below the installation, the Knights infiltrated Fortress Vader, with the spooked Knight Bazzra destroying Momin's helmet en route, and stole the Screaming Key from its vault before departing Mustafar. While many defending Lava Troopers had been killed, Vaneé survived the ordeal and the Knight Fyodor perished by the hand of Lord Vader, who learned of the legendary Knights of Ren's existence.

The Eye of Webbish Bog called out to Vader, who entered his lair and experienced visions that the being hoped would serve as a warning to the Sith Lord of an impending culmination of interconnected galactic events. After receiving the visions, Vader found that the Eye was being poisoned by a device left in his cave and subsequently ambushed by several Mustafarians. The natives were unhappy with the Sith Lord's intrusion on their planet, but Vader dispatched them at the cost of only a scar left on his helmet and eliminated the device that had been plaguing the Eye. The Sith then returned to his castle, where he spoke with the Emperor via hologram about Lady Qi'ra's machinations against them.

After the Sith overcame Qi'ra's attempt to defeat them, Luke Skywalker communicated with a red kyber crystal on the planet Christophsis, in the process experiencing a vision in which he saw Fortress Vader in the midst of a red lightning storm as well as his father, Darth Vader. Qi'ra's activation of the Fermata Cage during her war against the Sith had destabilized Vader's mastery of the Force, and the Dark Lord, wielding the Zaly Shield alongside a staff, returned to the lava fields before his castle to train himself in focusing his powers. Meanwhile, the Scourge, a droid-possessing malady, intended to control Vader as he was a cyborg who could use the Force. It arrived on Mustafar as the corrupted rebel protocol droid C-3PO and a the MSE-6 droid Petyr on a Taylander shuttle to Vader's castle. The initial attack on Fortress Vader failed as the Scourge's attention was diverted by an attack elsewhere and the breakthrough of being able to control the consciousness of cyborg organics.

While training with his droid army, Vader received a hologram transmission from Grand Vizier Amedda, who relayed the Emperor's order to reclaim his flagship, the Executor—it had been infiltrated by the Scourge. Vader and his droids thus departed for the Executor aboard an Imperial transport. After successfully reclaiming the flagship, the Sith Lord took his droids and his personal TIE fighter and returned to Mustafar, where another droid repaired its fellow veterans while Vader confronted the Eye of Webbish Bog, demanding power and control—while battling the Scourge, Amedda had ordered the Executors destruction with Vader onboard. The Eye reminded Vader that power lied with his master, Darth Sidious, citing the Tragedy of Darth Plagueis the Wise in which Sidious murdered his own master. While Vader prepared to depart for Coruscant's Imperial Palace with his droids and a Lambda-class shuttle, one of his droids, ZED-6-7, succumbed to the Scourge and activated an octuptarra tri-droid in the secret Techno Union droid factory.

The octuptarra attacked Vader on the lava plains, and the Sith Lord's crude Force power through his Zaly Shield and staff proved ineffective. In their attempt to trigger Vader's hatred so that he could further draw on the dark power that hate channeled, the Dark Lord's droids Gee-Ninety and Arex joined in the attack, but to no avail. Arex urged the Sith to think about what he hated most, and the cyborg realized that he hated himself; using his self-loathing, Vader channeled his hate into fine Force power to destroy Gee-Ninety, Arex, and the Scourge's octuptarra and ZED-6-7. Vader also found that he hated his master, Darth Sidious, even more than himself, and set off for Coruscant with his remaining droid, Ought-Six.

Toward the end of the Galactic Civil War, Vader was saved by the selfless compassion of his son, Luke Skywalker, and in turn sacrificed himself to destroy the Emperor aboard the second Death Star during the Battle of Endor in 4 ABY. Having re-embraced his identity as Anakin Skywalker as he succumbed to the injuries inflicted upon him by his late Sith Master, Vader died leaving his fortress without a host. After the battle, pilot Wedge Antilles scouted suspected Imperial planets and reported his findings to the leadership of the New Republic—the Rebellion's successor state—on the world Raydonia; due to Mustafar's proximity to Raydonia, Admiral Gial Ackbar sent a scout to there, along with the planets Tatooine, Dermos, Geonosis, and Akiva.

Following news of Darth Vader's death over Endor that the Rebel Alliance had broadcasted, Mustafarians gathered around the fortress' vicinity in celebration. Lightning storm clouds and lava on Mustafar stirred around Vader's castle, howls sounded in the night, and cries echoed across the lava plains. The Mustafarian boy Giggek recognized that his kind were not truly free as long as they lived under the shadow of Vader's castle, and so resolved to rid the land of Vader's curse by bringing the castle to ruin. Along with Tuttel, Giggek acquired detonators from a store of equipment from the obsidian mines belonging to Tuttel's uncle, Lellis. However, the latter forbid the young boys from entering Vader's castle for the reason that it was lethal and evil, telling the story of how Vaneé came into servitude under Vader and further speculating that the young Mustafarians were only pursuing glory.

Nevertheless, Giggek led Tuttel into Vader's castle by way of lava flea, venturing in to find a pit trapping Vaneé, the servant of Vader and the self-styled "one true Acolyte of the Beyond" who was detained by Vader there some time ago. Rescuing the Acolyte in hopes of not bringing death upon anyone in the process of destroying Vader's castle, Giggek was at once betrayed by Vaneé, who dropped the boy down the pit in hopes of bringing death to those who sought to tarnish his master's legacy. However, after instructing his Mustafarian companion to flee, which Tuttel did with their lava flea, Giggek ignited his explosives through a remote detonator, and although the blast did not bring down Vader's castle, Vaneé was buried in black sand. However, the Sith servant survived. A voice familiar to Vaneé told him not to fear, and assured its servant that he could return Vader to the fires of Mustafar and be made whole.

Following the Empire's defeat at the Battle of Jakku in 5 ABY, Vaneé told the voice he believed to be his master that everyone in the galaxy believed that he was dead, which the supposed ghost of Vader replied to by saying that the Sith can never truly be killed since it was the will of the dark side. Vaneé then orchestrated a ritual in which Vader's ghost reached out across the galaxy to imprint nightmares upon others' minds. One such nightmare reached Milo Graf, brother of Lina Graf, in which Milo had a nightmare about undead droids and himself being taken to Mustafar by CR-8R, controlled by Vaneé.

After he discussed Vader's castle with his sister and CR-8R, Milo Graf and the droid went missing for days—CR-8R had been afflicted by a signal that scrambled his processors and had incapacitated the organic before bringing him to Vaneé on Mustafar. Suffering from a dream of her brother being trapped on Mustafar, Lina requested New Republic Chancellor Mon Mothma and Senator Leia Organa on the capital world Chandrila to spare a ship to investigate the lava world, which had remained under Imperial control. Although Mothma denied Graf's request, Organa suggested that she contact the smuggler Jaxxon T. Tumperakki for passage to Mustafar. Before arriving at Vader's castle, they enlisted Graf's old crew, Thom Hudd and Skritt; Hudd had also been experiencing nightmares related to Vaneé and the fortress.

En route to Mustafar aboard the Rabbit's Foot, Lina Graf experienced a nightmare where her crew was attacked by an Imperial Gozanti-class cruiser and TIE fighters upon arriving in the Mustafar system. Mid-battle, Lina Graf was attacked by the phantom of Darth Vader and encountered her brother, Milo, who transformed into Darth Vader and killed her crewmates. When Lina awoke from her nightmare, her crew and their ship had landed at Fortress Vader. While the crew broke into the installation, Lina was contacted by Milo via comlink, pleading to be rescued. They then encountered a machine resembling Darth Vader and wielding a blue-bladed lightsaber, but promptly destroyed it and found CR-8R, who regained his normal processing and revealed Vaneé to be the mastermind.

Vaneé soon captured the crew, intending to use them for a ritual that supposedly would revive Darth Vader. He released lava fumes into the captivity chamber, declaring that Lina Graf would be the vessel for Vader's return and that the Dark Lord would be immortal, ushering a new empire. However, Lina saw through Vaneé's madness and the hallucinations brought by the lava fumes, conquering her fear; taking advantage of Vaneé's fear for Vader, she deceived the man and freed her crew with the blue lightsaber. Upon forcing Vaneé into the restraints that he had used to detain her, Lina fled just as her blade extinguished, leaving Vaneé trapped with his own nightmares within the castle. Before departing Mustafar safely, however, the Lina's crew followed the light of a blue blade in order to flee Fortress Vader—unbeknownst to them, the light was created by the Force spirit of Anakin Skywalker, Jedi Knight.

Mustafar grew in obscurity in the decades that followed, and Vader's castle eventually fell into ruins. Thanks to the destruction of the Bright Star, Mustafar's ecosystem began to be healed. Several individuals from off-world also visited the planet, including the spy Vi Moradi as well as the historian and adventurer Eloc Throno, who wrote of the world in Volcanic Planets: Your Guide to the Galaxy's Hottest Destinations, one of the many travel guides he wrote throughout his career. By 35 ABY, many pilgrims had come to the ruins of Vader's castle seeking to tap into the Sith Lord's dark power. One group of pilgrims, the Alazmec of Winsit, guarded the castle ruins as well as its secrets jealously, colonizing the nearby Corvax Fen and planting a forest of irontrees in the hopes of restoring Mustafar's once lush landscape from centuries ago, believing that the soil was soaked by the tears of Lady Corvax. The cultists cared for the trees as they sought to connect to the power of the Sith.

After the First Order nearly destroyed the Resistance at the Battle of Crait in 34 ABY, the pirate Hondo Ohnaka wrote about Mustafar in his book Galactic Explorer's Guide. Around the same time, the confused pilot Shriv Suurgav uttered "what in the depths of Mustafar?" during his mission to acquire starfighters for the Resistance when First Order stormtroopers he was fighting began to be hit by arrows from the Bracca resistance.

In 35 ABY, the First Order Resurgent-class Star Destroyer Steadfast arrived over Mustafar following a mysterious broadcast from the resurrected Darth Sidious. Knowing that Mustafar was once ruled by his grandfather, Darth Vader, Supreme Leader Kylo Ren regarded it as hallowed ground—the place where Anakin Skywalker died and a Dark Lord of the Sith was born.

Landing in his TIE whisper with General Armitage Hux and Allegiant General Enric Pryde observing him from afar, Kylo Ren rallied his forces to Mustafar as part of his search for answers to confront whoever was behind the transmission. The Supreme Leader and his stormtroopers slaughtered the cult of Alazmec colonists near the ruins of Vader's castle, who were sworn to protect the surrounding fen. Afterward, Ren traveled through the fen and arrived at a small lake, where he encountered the Eye of Webbish Bog.

The Eye knew what Ren sought but warned him of encountering his "true self" if he were to continue down his current path. When Ren did not respond, the Eye relented and rewarded the Supreme Leader for his victory over the Alazmec, pointing the way to Vader's Sith wayfinder. Ren was guided by wisps of the dark side and came to an altar surrounded by the fortress ruins where he found the wayfinder. The Eye of Webbish Bog and the giant then disappeared into the lake, leaving Ren alone with the artifact. Knowing that he would not be the only one to travel to Mustafar in search of the object, Ren, with the word "Exegol" suddenly in his thoughts, departed the planet with the rest of the First Order forces. The Eye's prophecy soon came true: Ren reached the planet Exegol, where he found the resurrected Sidious with his Sith Eternal followers, and eventually returned to abiding by the light side of the Force, joining the Jedi Rey to destroy Sidious once and for all, ending the galactic war.

Boasting a population of approximately 15,000 to 20,000 individuals, Mustafar was the homeworld of the Mustafarians, a species primarily concerned with their own advancement and survival that lived in underground caves created by the lava fleas that ate through the planet's crust. Two races of Mustafarians evolved in distinctly different cave systems in the mountains from extremophile arthropods, one subspecies living near the planet's equator and the other in the north. They lived together as needed, although the geographical distance and limited desirable living space tended to limit the subspecies in their own communities.

Only venturing up to the surface in order to collect valuable minerals from the lava flows, the southern Mustafarians carried out the heavy labor involved due to their short and strong physiology that developed due to the relatively higher gravity of their homeland, surviving high temperatures and frequent accidents on lava flows thanks to their thick carapaces, while the tall and slender northern Mustafarians had keen, faceted eyes which easily spotted flaws in ore and machinery alike, and who acted as guards and expert riders of the lava flea, a creature that the natives made their armor from the heat-resistant shells of.

Chitinous exoskeletons and low-water biology allowed Mustafarians to withstand the intense heat of their homeworld, although they still required insulated clothes and breathing apparatus to work on the surface. The native Mustafarians developed and sought technology for survival more so than most other species, and some enhanced themselves with cybernetics to better carry out common tasks and withstand the harsh environments of their homeworld. Having learned from tragic experiences, Mustafarians did not trust imported technology until they themselves modified and adapted them to Mustafar's climes. While the two Mustafarian subspecies lived together as needed, the geographical distance and limited desirable living space tended to keep them in their own communities, although it was not unheard of for clans to be comprised of both northern and southern Mustafarians.

The Mustafarians grew few crops, as the lack of water meant traditional farms, even when located underground, could not be sustained; water had to be imported to Mustafar. Nevertheless, despite the what little life Mustafar had compared to other worlds, various types of edible fungi and domesticated herds of large insectoid creatures made up much of the Mustafarian diet, and unlike other hotbeds of industry in the galaxy, Mustafar was largely self-sufficient in regards to its food supply.

Southern Mustafarians made Mustafarian Lava Buns by placing sweet balls of dough upon the planet's volcanic crust, heating it up to create a red bread with a cracked and blackened exterior. The Artiodac chef Strono Tuggs witnessed the production of the baked goods during a visit to Mustafar, learning the recipe to the buns in the process. Tuggs later served the buns at his mobile restaurant on the Outer Rim planet Batuu after the fall of his previous place of employment on Takodana in 34 ABY.

Although they typically inhabited natural caverns and abandoned mines, Mustafarians built outdoor structures as necessary, including saucer-shaped buildings at and near active mining sites. Their structures were strongly reinforced and armored to protect them from natural disasters, making their larger facilities fortresslike in construction and durability.

The Mustafarian people shared a deep connection with their planet, seeking harmony with the natural forces that sculpted their homeworld. Surrounded by volcanic magma, their culture was tied to the ebbs and flows of the lava on which they lived. In the difficult times of the Empire, history and lore of Mustafar lived on in a Mustafarian leader known as the Priestess, who provided guidance and invaluable information to natives and visitors alike. The natives lived in clans, and members of Father Kkkt's clan spoke of "lifefires" and "endfires" while discussing the arrival of Darth Vader; Kkkt himself used the Force to form a symbol within a lava river, which he interpreted as an omen of the planet's future. The Mustafarians had a strong desire to protect their homeworld, banding together on multiple occasions to defend against Imperial forces. They had a special relationship with the other life on Mustafar; lava fleas were used to jump over lava flows in a rite of passage, and kahel cave fungi served as the inspiration for Mustafarian architecture. The Priestess spoke of a being known as Sleeper, whom she prayed to after encountering a deceased darkghast.

Mustafarians were politically organized in accordance with the caverns and communities they inhabited, although they had little in the way of a central government. However, some trusted leaders were allowed to make deals with offworlders in order to help ensure their survival and quality of life. As a result, the Mustafarians fell under the sway of the Techno Union and later the Mining Guild, serving them as ore scouts, miners, and refinery laborers. While they resented the presence of offworlders, Mustafarians were generally willing to tolerate a degree of outside political influence as long as it furthered their own cause. Because of the demanding environment of their world, Mustafarians were generally insular and disinterested in galactic affairs, few regarding offworlders with much curiosity. Their focus on the advancement and survival of their own species overrode other concerns, a result of inhabiting a world that demanded so much in order to so much as continue living.

Mustafarians spoke a language of the same name, which allowed for the precise expression of concepts related to naturals features above and below ground, especially phenomena that were deceptively dangerous. Although the Mustafarian subspecies spoke different dialects, any two individuals could communicate on a functional level despite differing terms and cultural concepts. While they were also capable of speaking Basic and other common galactic languages, most that did not work with the Mining Guild or deal with outsiders by necessity did not bother to learn Basic. However, Mustafarians that lived or traveled offworld almost always spoke Basic and sometimes the language of their trading partners. Due to their history with the Techno Union, they were more likely to know languages regularly used among former Separatist worlds.

Mustafarian travels off-world were driven by business pursuits and trade negotiations, and were generally restricted to the Outer Rim. So long as their safety or that of their companions was not threatened, the species was disinterested in galactic affairs, which made them foremost disinclined to leave their homeworld. For Mustafarian merchants and Mining Guild personnel, regular trips were made off-world to trade for upgrades in protective technology and equipment, as well as to deliver ores to buyers. However, there were some Mustafarians who sought full-time employment off-world. They found most inhabited worlds cold, yet relished the relative safety.

The Techno Union, a guild of technology firms led by Skakoans like Wat Tambor, came to value the lucrative minerals of Mustafar and set up operations on the planet. The offworlders introduced heavy industry, and were welcomed by the native Mustafarians in exchange for access to mining droids and heavy-duty speeders. However, the natives became subjugated, being put to work in the Techno Union's mining operations and charged rent on their own planet. Management staff of the Union utilized native buildings throughout their operations and provided a refuge for the Separatist Council during the final days of the Clone Wars. Mining droids used on Mustafar during its time under Techno Union ownership included the ore extraction droid, the DLC-13 mining droid, and the electrorefining droid. A number of Separatist battle droids and mouse droids were also present within the facility used by the Separatist Council in the late Clone Wars.

Aside from the native people and the Techno Union, Mustafar was also inhabited by Falleen, tall and muscular reptomammalians native to the Mid Rim planet of the same name that controlled the vast Black Sun criminal empire. Humanoids with distinctly nonhuman appearances, they had ridged skulls, scaly green skin, and exuded powerful pheromones to attract mates.

The Sith Lord Darth Vader called Mustafar his home during the Imperial Era. Originally coming to the planet in hopes of resurrecting his deceased wife, Vader lived on the volcanic world for over a decade, utilizing its scorched earth to conduct his personal business, and ruled the entire star system from his castle and its throne room. Stories of the Jedi who died by his hand on Mustafar became synonymous with the planet itself. During his visit to Fortress Vader, Director Krennic theorized that Mustafar was Vader's homeworld, imagining that the Dark Lord's cybernetics were designed to allow him to survive while away from the molten planet. The Sith Lord's occupancy was known to others in the galaxy as well. After discovering that Mustafar was Vader's domain, the Naboo resistance group known as the Amidalans deduced that he was responsible for Padmé's death and plotted to kill the Dark Lord to avenge the fallen queen.

As Darth Vader established his personal headquarters on Mustafar, the forces of the Galactic Empire followed. The Imperials' occupation of the planet forced Black Sun and the Techno Union to abandon their operations, with the Mining Guild taking over what remained. Within both Vader's fortress as well as other installations, the Imperial Army had a sizable presence on the world, enough that the native population sought to remove them from the planet. Stormtroopers guarded Imperial interests on Mustafar; among their ranks were magma troopers and Lava Troopers, specialized soldiers that operated within the planet's volcanic environment.

Many groups of cultists came to Mustafar in the decades since Vader's passing, seeking the power that the Sith Lord once tapped into on the planet. One of those groups, called the Alazmec of Winsit, gained control of Corvax Fen. They planted several irontrees in its fertile soils in the hopes of restoring the landscape that was once present centuries ago, and were devoted to guarding it from outsiders such as Kylo Ren and the First Order. Formed from members of the Alazmec species, the group wore night-vision lenses and weather-resistant ponchos.

In the planet's vibrant past, the Mustafarians shared the world with Lady Corvax and her husband Dorwin, humanoids who lived peacefully with the natives. Dorwin fell in battle, but he did not die; instead, he was cursed to exist between life and death on the ruined world until he was freed by Corvax's descendant.

The ancient Sith established a presence on Mustafar, hoping to reap the benefits of the dark world and obtain immortality. At some point, the Sith Lord Momin found himself on Mustafar, and later, during the Imperial Era, recalled that long ago time.

Two mysterious beings resided in a lava cavern near Fortress Vader—the spider-like Eye of Webbish Bog atop a blind giant, who were submerged in their lair and were locked in a symbiotic relationship. Their lair became a small lake beside the Corvax Fen, and they guarded the path to the ruins of Vader's castle. Spoken of in the myths of the Mustafarians, the Eye was defended by the Alazmec of Winsit.

The native Mustafarian populace, including both the Northern and Southern sub-species, took up residence in underground caves that were made by lava fleas munching through Mustafar's crust. Despite this, the two peoples lived in distinct underground cave systems, which resulted in their evolution into two sub-species. The Mustafarians' underground buildings were designed in the shape of kahel cave fungus, which was highly symbolic in Mustafarian culture.

Due to the planet's fiery surface, outdoor structures were built where necessary—usually at and near active mining sites—and buildings on Mustafar were held up by stem-like gravity supports. Its capital city was Fralideja, one of the few remaining Mustafarian settlements at the time of the Clone Wars. A cataclysmic eruption that occurred centuries before the war's end almost destroyed the entire local population. The city and its surrounding structures were of Mustafarian architecture: mushroom-like structures with a habitation dome raised from the scorched ground, based on the shape of the local culture's highly symbolic kahel cave fungus. The saucer-shaped structures were strongly reinforced and armored against natural calamities, with larger facilities on Mustafar becoming fortresslike in construction and durability. Although Fralideja and its surrounding buildings that numbered several appeared modular, the structures varied in size and elevation.

Another settlement was a mining town known as Zitontown, named for Ziton Moj, a senior Black Sun Vigo who rose to leadership of the organization during the Clone Wars. Located outside of town was as a fortified cliffside facility that served as the organization's headquarters during the conflict. The installation's architecture was distinct from other facilities located on Mustafar. Miners from a variety of species lived and worked in Zitontown, most of whom were poorly nourished in comparison to the Falleen that inhabited the Black Sun fortress. In addition to the fortress, Moj also possessed a palace.

During the Clone Wars, Darth Sidious secretly maintained an old mining outpost on Mustafar, planning to use the facility to train Force-sensitive children to become his agents. The Sith tasked the bounty hunter Cad Bane with kidnapping children and delivering them to the facility for their training. However, it was destroyed by Sidious' crew of nanny droids after Anakin Skywalker and Ahsoka Tano rescued multiple kidnapped children from the facility.

Mustafar was famous for its , and was typically used by spacers to refuel their vessels. The Techno Union maintained multiple mining operations on Mustafar, including a complex built into a lava-filled mountain—which also housed a secret battle droid factory—and a nearby residence for technicians and mine management staff located opposite to the capital city Fralideja. Around the area was a molten rock plain with erupting lava geysers that were repressed by the facility's repulsor fields. In addition to containing a secret command facility, the structure served as cover for a Techno Union droid production operation concealed inside the mountain upon which the mine sat, manufacturing battle droids for the Separatist Droid Army. The repulsor fields that protected the complex were inadvertently deactivated during the duel between Obi-Wan Kenobi and Darth Vader and the facility soon fell into ruin.

Fortress Vader was an obsidian tower built by Lord Momin and Darth Vader as the latter's personal retreat on the Gahenn Plains during the Imperial Era. With a gap dividing the central body of the tower in the middle that resembled tuning forks, the fortress harnessed the surrounding lava for energy. It was also designed to channel the dark side's power, and, along with being near the site of the Sith Lord's duel against his former master Obi-Wan Kenobi, it was located above an ancient Sith cave to provide a more powerful locus of the dark side for Darth Vader to draw upon. It was also on the site of the underground fortress of Lady Corvax. When visiting the fortress, Imperial officers were intimidated by the surrounding environments, and the treacherous landscape of Mustafar worked to remind them of their place. Vader's castle had an Imperial base in its vicinity, which housed a part of the garrison protecting Vader's sanctum.

Formerly a part of a Sith temple, the cave beneath Vader's castle contained a locus of the dark side of the Force. The walls of the cave were covered in glowing runic symbols, which Vader and Momin later rearranged to focus the energies of the planet. By tapping into the dark powers of the locus, an individual could open a rift between time and space to enter a portal through the Force. Darth Vader also forged his first red lightsaber at the cave, and Snoke, the First Order Supreme Leader who trained Kylo Ren, wore a ring that featured obsidian carved from the same cave.

Corvax Fen was a vaguely hospitable bog that contained irontrees, being one of Mustafar's few such places. Located close to the ruins of Darth Vader's fortress, the fen was guarded by the Alazmec of Winsit, a group of cultists devoted to the Sith Lord. Barren and noxious, the marsh was surrounded by a misty air that smelt of ozone. It contained a shallow lake of brackish water that was covered in an oily film.

By 1977, George Lucas conceptualized the creation of Darth Vader happening after a duel with Ben Kenobi and the father of Luke Skywalker. The father is killed by Vader, who is confronted and nearly killed by Kenobi. Vader falls into a volcanic pit and is severely injured, necessitating his use of cybernetics. At one point, the duel's location was named Sullust, a lava planet that was given a passing mention in the 1983 film Star Wars: Episode VI Return of the Jedi. The concept of a lava duel was revisited in the earliest versions of Return of the Jedi. In those versions, Luke Skywalker fights Darth Vader over a lava lake in the Emperor's Throne Room, located in a cave in the lowest levels of the Imperial capital Had Abbadon. Although this was visualized by veteran Star Wars concept artist Ralph McQuarrie, the concept was not carried over to the final script. The concept of Kenobi dueling Vader, while altered with Skywalker's father now being Vader himself, was realized in Star Wars: Episode III Revenge of the Sith, twenty-eight years after the original film.

Released in 2005, Revenge of the Sith marked the first appearance of Mustafar. Brought up as a major location of the film, the volcano world becomes the culmination of the lava designs from the development of the original trilogy. Whilst the planet is named "Mufasta" in earlier concepts for Revenge of the Sith, the finalized spelling was in place by October 25, 2002; George Lucas had decided to dedicate about twenty to thirty minutes screen time to the planet he respelled, and planned to include a major fight as well as a "love scene" there. Despite the new spelling, draftspeople and model-makers working on the film in Sydney, Australia spelt the planet name as "Mustafa" when labelling an early 3-D rendering of the lava world's Separatist war room. "Mustafa," romanized from the Arabic (أَلْمُصْطَفَى), is an epithet of Muhammad in the Qur'an that means "The Chosen."

Writer-director George Lucas intended the lava planet to symbolize the Biblical hell. Lucas also said that Anakin Skywalker's injuries that were inflicted by Mustafar led to the loss of his power in the Force; Darth Sidious' plan for his new apprentice to become more powerful than himself was derailed by Obi-Wan Kenobi.

Before Lucasfilm artists finished work on the 2002 prequel trilogy film, Star Wars: Episode II Attack of the Clones, George Lucas wanted ideas of what his lava planet for Episode III would look like. Prequel trilogy concept artist Doug Chiang had previous made sketches of Mustafar's volcanoes, as well as a castle on the world. The Episode III art department began working in early 2002, and at Skywalker Ranch, artists conceptualized Lucas' lava planet as either a technologically advanced world or a wild, primordial location.

Concept Design Supervisor Ryan Church made concepts of both using Corel Painter, and one such piece featured Gothic constructs of skyscraper proportions. When Lucas was shown one of Church's more abstract and fanciful concepts for Mustafar, the director said that he wanted a more grounded design.

The concept artists who worked on Mustafar for Episode III include Concept Design Supervisors Ryan Church and Erik Tiemens, Aaron McBride, and Derek Thompson, amongst others. McBride originally designed the Pau'ans seen in the final film as natives of Mustafar, although Lucas decided to use his designs for the residents of Utapau by 2004.

After the artists made a variety of concepts, such as controlled mineral-harvesting environments complete with lava dams as well as an orbital ring structure that siphoned energy from the lava world, the two extremes ultimately coalesced into what became of Mustafar: a blend of lava-reliant technology and an untamed hellscape. With Lucas stating that the film would begin with seven battles on seven planets in June of 2002, Church made his ring world concept as a Star Wars take on a Dyson sphere. In addition, Church conceptualized a Venator-class Star Destroyer crashing on the world as a result of a battle overhead—he had little knowledge of the plot at the time, and thought that the duel between Kenobi and Skywalker could start on the ship and continue after it crashes on the surface of "Mufasta." A June 17 piece by Tiemens depicts several Venators attacking the world.

Since Lucas insisted that designs for different worlds be instantly distinguishable, owing to the many new planets introduced in Episode III, Church first made a sketch of a Mustafar chamber without color, dated to September 26, 2002. While the Episode III artists did not know the function of Mustafar beside the apparent ending when it was made, the piece features an imposing "alien-imperial" throne. A later piece by Church conveys the magnitude of the world's dangers by showing various technological apparatus keeping a Mustafar bunker together amid lava dams and lavafalls, with a Venator-class Star Destroyer docking at the facility. Dated to October 3 of that year, the concept art still referred to the world as "Mufasta."

George Lucas revised his drafts for the film as the concept art for Mufasta developed, and left details of the duel between Vader and Kenobi untouched for guest director Steven Spielberg to form ideas for, based on concept art approved by Lucas during his meetings with the art department. During an art department meeting, Lucas relayed Spielberg's idea that Vader and Kenobi fight on an extended arm of a Mustafar facility that would break off and fall into the lava flows below. Another idea involves Vader and Kenobi taking shelter behind a ledge as a screen of embers fly down from a spurt of lava, bouncing around and catching on fire. To explain the arm breaking off the Mustafar facility, the art department suggested to Lucas that the film shows lava melting through the structure. Along with animatics supervisor Daniel D. Gregoire, Spielberg helped pre-visualize the Mustafar duel as well as the the Utapau chase scene, both as a favor to Lucas and to learn the latest pre-visualization methods for his own 2005 science fiction film, War of the Worlds.

Having heard news that Mount Etna, a volcano on the island of Sicily in Italy, was erupting in late October, 2002, George Lucas asked film producer Rick McCallum to arrange the filming of the ongoing volcanic eruption for Mustafar's imagery. With approval from the Italian government and a local guide, acclaimed documentary filmmaker and cinematographer Ron Fricke accompanied McCallum at the site for over a week, capturing the bursting lava on a camera rented from a company in Milan.

Amongst other images, lava fountain elements shot by Fricke were incorporated by digital matte artist Brett Northcutt at the Digital Environments department into an animated background cyclorama used in Revenge of the Sith. A mesh of various assets that also included stills of gravel at the Industrial Light & Magic parking lot and computer generated images, the matte painting comprised of 25,000 pixels and took several months to make, and served as the backdrop for Mustafar in the film.

Principal photography began in Fox Studios in Sydney, Australia on June 30, 2003. On July 13, from Skywalker Ranch, Ryan Church made another Mustafar piece to communicate to various film departments of the layout of the Mustafar duel. The piece gives a general idea of the environment in which it would take place and the direction of the battle.

Revenge of the Siths main model for Mustafar measured eight meters wide and eleven meters long, and was used for establishing shots of Mustafar's surface surrounding the mining facility. Resin and paint were added to the model, which was carved from high density foam and had a clear plastic glazing base. Between the rocky elements, the model revealed three channels of the transparent plastic for the flow of simulated lava—which was made from tens of thousands of litres of methocel with yellow dye. In order to achieve the effect of oozing, glowing lava, ILM employees such as initially poured buckets of methocel into the upper end of the model, which they tipped by ten degrees, and placed studio lights of 250,000 watts beneath the plastic channels that the "lava" through. The thickness of the methocel determined the varying shades of red, orange, and yellow resulting from the creative lighting, and black powdered cork was further sprinkled onto the liquid to simulate rocks being carried by the lava flow. An elaborate pump and filtration was installed to recycle the methocel from the bottom on the model back up to the top, maintaining its steady movement.

ILM further filmed faux explosions using additional methocel on an outdoor lot, as well as the lava bank at the end of Vader and Kenobi's duel—combined with their main lava flow model, Mustafar's model sequences took ILM eight months to film—the longest model shoot in the company's history. The final visuals of the fighting sequence comprise of multiple motion-control shots of the main model, digital animation, and close up and action shots of Anakin Skywalker actor, Hayden Christensen, and Obi-Wan Kenobi actor, Ewan McGregor. George Lucas and editor Roger Barton further incorporated the Mount Etna footage as both their own frames and as elements within other shots of the Mustafar sequences. When Vader and Kenobi fight on the fallen mining complex arm, the lavafall flows backwards as a result of an edit by George Lucas to ensure the camera follows the duelists in a single direction as they progress.

An earlier version of the story for the Star Wars: The Clone Wars Season One episode "Liberty on Ryloth" featured Mace Windu rescuing Twi'lek captives from a prison suspended over a volcanic caldera. Although this was cut when production paintings of the setting ended up looking too similar to Mustafar, the location was revived for the Season Four episodes "Slaves of the Republic" and "Escape from Kadavo" as the Kadavo slave processing facility.

Mustafar itself made an appearance in the show's second season episode "Children of the Force," serving as the final destination of a three-part arc in the series. Development of the planet for the show was challenging for the Clone Wars team, as the lava and explosion visuals required for the episode called for significant effects work. Supervising director Dave Filoni also noted that Mustafar's inclusion in the show was initially difficult for him as a fan; to him, the planet was too important to Anakin's story in Revenge of the Sith to be included earlier in the timeline. George Lucas, however, convinced him that Mustafar served as the ideal location for the arc's finale, prompting Filoni to rationalize that the world was not likely to be unknown to the galaxy at large, further reasoning that the planet's perceived significance among fans was superseded by the needs of the story.

According to effects supervisor Joel Aron, some of the elements of Mustafar's lava from Revenge of the Sith were repurposed for the Well of the Dark Side on Mortis in the episode "Ghosts of Mortis."

Mustafar was later featured in the 2016 Star Wars Anthology film, Rogue One: A Star Wars Story. It was the site of Fortress Vader, a stronghold where Darth Vader resided. To prepare for the planet's return to film, art director Doug Chiang and the design team revisited Ralph McQuarrie's old designs for Mustafar and combined them with its depiction in Revenge of the Sith in order to create a unique aesthetic. Fortress Vader was created based off of a few of McQuarrie's designs, including a series of paintings and sketches of an underground lava cave, with the Emperor's throne on Had Abbadon interpreted instead as Vader's throne in the Sith cave beneath the Dark Lord's castle. It was also designed to look like a tuning fork, to represent the structure being attuned to the Force, similar as the Temple of the Kyber in Rogue One. Interior concept designs for what eventually became the stronghold were created by Ryan Church, Matt Allsopp, Luke Fisher, Julian Caldow, Thom Tenery, Brett Northcutt, and Erik Tiemens, while the landscape was drawn by Allsopp and Christian Alzmann.

The planet was featured in the opening scene of the 2019 sequel trilogy film Star Wars: Episode IX The Rise of Skywalker, in which Kylo Ren leads a First Order attack on Mustafar to obtain a Sith wayfinder. While the final film features only about a minute of screentime for the world, additional scenes were originally planned. Actors Domhnall Gleeson and Richard E. Grant, who played the First Order leaders Hux and Pryde, respectively, have stated that at one point their characters were meant to accompany Ren to Mustafar. Although the actors did indeed film the scene, it was removed from the final cut of the film. Gleeson and Grant expressed a desire to see the scene released on home media, but the footage was never provided. A version of this scene was later included in Rae Carson's 2020 novelization of the film.

Another deleted scene, featuring Ren's encounter with the Eye of Webbish Bog on the planet, was filmed near the United Kingdom's Pinewood Studios in a lake at Black Park. According to creature and special make-up effects creative supervisor Neal Scanlan, the scene was cut due to its long length and concerns with conveying information to the audience effectively. This scene also went on to be included in Carson's novelization, as well as in Michael Kogge's junior novelization later that year. The two works present different interpretations of the sequence, however. In Carson's book, Ren wades through the Eye's lake to reach a small island and obtain the wayfinder, whereas Kogge's adaptation depicts the creature pointing Kylo beyond the lake and towards the remains of Vader's fortress. This article assumes neither story has canonical precedence over the other and presents a combined version of these events.

Mustafar is among the various locations showcased in a montage promoting the Stormtrooper Corps during the stormtrooper Candace's performance of the song "In the Empire" in the 2014 non-canonical film Phineas and Ferb: Star Wars. In the 2020 mobile video game Star Wars: Starfighter Missions, Mustafar appears as one of the locations over which starfighter battles take place.

In Stuart Beattie's script for a cancelled Obi-Wan Kenobi feature film that later evolved into the 2022 Obi-Wan Kenobi television series, Kenobi would fall in with refugees that are fleeing from the Empire. Tao, the lead refugee woman, takes Kenobi to a sacred shrine and instructs the Jedi Master to let their goddess speak to him. Later on Mustafar, Kenobi experiences a vision in which he is attacked by Luke Skywalker, who almost kills him. Kenobi then realizes that putting his guilt on the young Skywalker would turn himself to the dark side of the Force. The duel was intended to mirror the dark side cave scene in the 1980 film Star Wars: Episode V The Empire Strikes Back.

First published on StarWars.com on June 24, 2022, and written by Emily Shkoukani of the Lucasfilm Story Group, Star Wars Inside Intel: The Inquisitorius stated the moon of Nur, where the Inquisitorius maintained their base of operations and was featured in the Obi-Wan Kenobi series, orbited Mustafar. However, in 2023, the article was updated to remove this, instead more simply stating the moon was located in the Mustafar system. Although the 2023 reference title Star Wars: Dawn of Rebellion: The Visual Guide also states that Nur orbited Mustafar, the 2020 reference title The Star Wars Book simply states that Nur was a moon in the Mustafar system, which this article maintains rather than assume further.

In the 2015 non-canonical LEGO Star Wars: Droid Tales series' "Crisis on Coruscant" episode, the droid C-3PO recounts the events of Revenge of the Sith, including the duel on Mustafar: the fight ends with Obi-Wan Kenobi accidentally pushing Anakin Skywalker straight into lava.

In the 2023 non-canonical verbal short "The Sith Witch of Mustafar" of the LEGO STAR WARS: Celebrate the Season animated anthology series, Darth Sidious finds his apprentice at his castle on Mustafar on Halloween and complains that he had searched the galaxy for him, and insists that they return to Sidious' shuttle to get on with their work. Vader reluctantly follows his master out of the castle and warns about an alleged "Sith Witch of Mustafar" who haunted Mustafar's spooky landscape. Although Sidious kept dismissing Vader's warnings, they are frightened by signs of the alleged Sith Witch when they walk into the middle of the woods in a swale. However, the Dark Lords discover that they were merely found by stormtroopers dressed up for Halloween, and Sidious allows each trooper to take one Halloween sweet from him. The Sith then continue walking to their shuttle as the troopers leave, but are spooked by R2-D2 dressed up as a ghost. To their distress, the trio subsequently find a great light in the woods.

In "Mech My Day," a non-verbal short of the series released on the same day, Vader is annoyed by the clumsiness of one of the stormtroopers who were cleaning his throne room in his castle. That stormtrooper constructs a personal mech suit, showing off the creation to fellow troopers before Vader. The angered Sith Lord builds his own mech and battles the stormtrooper, but they are interrupted by the bounty hunter Boba Fett, arriving from his ship to join the mech fight with his own mech suit. Fett destroys Vader and the trooper's mech suits as he flies through the ceiling of Vader's throne room, and the Dark Lord begins to punish the trooper.

In the 2020 non-canonical film The LEGO Star Wars Holiday Special, set after the events of The Rise of Skywalker of 35 ABY, the Jedi Rey Skywalker obtains a key on the planet Kordoku that allows her to travel through portals in time. Her activation of the key leads to Darth Vader from the past attempting to seize the key for himself, and during his lightsaber duel against Skywalker, the two, along with a pair of snowtroopers from the Battle of Hoth, arrive on Mustafar during the duel between Obi-Wan Kenobi and Darth Vader over a river of lava from a portal above. While Rey Skywalker and the Vader in pursuit of her continue their duel over two mining droids, the snowtroopers take the key on a mining platform and attempt to pass it to their commander, but Skywalker intercepts it through the Force. As the group approach a lavafall, Skywalker opens another portal over its crest, and all participants safely enter it and reach a battle on the planet Nevarro.

The 2021 non-canonical film LEGO Star Wars Terrifying Tales features Vader's castle on Mustafar, where the Dark Lord boasts of his new sanctum beside Darth Sidious before the pair leave, allowing Vaneé to look after the place in their absence. Later, after the end of the war against the First Order in 35 ABY, the Resistance pilot General Poe Dameron and his droid companion BB-8 make an emergency landing of their faulty X-wing in an irontree forest on Mustafar. Stranded, the pair enter Fortress Vader and find it being converted into a Sith-themed luxury resort by Graballa the Hutt and his Iktotchi henchmen, Baash and Raam. Dameron then meets the young mechanic Dean, whom he enlists to fix the X-wing, but they are blocked from doing so by Vaneé; he presents the helmet of Ren, who had been Master of the Knights of Ren before Kylo Ren. Working with the Imperial protocol droid NI-L8, Vaneé wishes to use Dameron to unlock Vader's treasures, based on a that foretold a fearless stranger would have the strength to do so.

After recounting the story of the rise of Kylo Ren, Vaneé, surrounded by bats, leads his guests to a repository of Sith artifacts, finding the Saber of Scardont and recounting its tale. While repairing the saber, Dean is mesmerized by its power and leads the group to the treasure-filled first , unlocking a Sith holocron as Vaneé delivers a tale of the Death Star. Vaneé then seizes the holocron and arms himself and NI-L8 leads an army of B1-series battle droids to attack the rest of the group. At the end of a battle against Dameron, Dean, and BB-8 in the forest and lava flow outside the castle, Dean hurls the holocron away; Vaneé jumps after it and is consumed by the lava below. Afterward, Graballa and his henchmen depart to launch a bed-and-breakfast business, while Dameron offers Dean a place in the Resistance as a pilot and to learn about the Force from Rey Skywalker before they leave with BB-8 as well. In the lava, NI-L8 emerges and is joined by Vaneé.

In the 2022 non-canon video game LEGO Star Wars: The Skywalker Saga, Mustafar is one of the worlds that players can freely explore and a setting in the story missions for Star Wars: Episode III Revenge of the Sith. It is also shown in cutscenes for Star Wars: Episode IX The Rise of Skywalker.

Elsewhere in the game, a Lanai Caretaker wishing to make invulnerable obsidian wheelbarrow on the planet Ahch-To's Temple Island asks the player character to find out where obsidian could be obtained, having been frustrated by the destruction of wheelbarrows during Rey's visit in 34 ABY. A Devaronian in the city Mos Espa on the planet Tatooine then suggests that obsidian could be found on Mustafar. On the planet Pasaana during the Festival of the Ancestors in 35 ABY, an Aki-Aki Storyteller describes the duel between "Dopi-Won" and "Panakin Slytalker" on an "oven" world to a group of Aki-Aki children as part of a puppet play. The stage's backdrop for the scene is a tapestry that depicts the mining facility on Mustafar.

• Phineas and Ferb: Star Wars
• LEGO STAR WARS: Celebrate the Season — "The Sith Witch of Mustafar"
• LEGO Star Wars: Droid Tales — "Crisis on Coruscant"
• The LEGO Star Wars Holiday Special
• LEGO Star Wars Terrifying Tales
• LEGO Star Wars: The Skywalker Saga
• LEGO STAR WARS: Celebrate the Season — "The Sith Witch of Mustafar"
• LEGO STAR WARS: Celebrate the Season — "Mech My Day"
• Brawlhalla