Having been found as a slave, the acolyte was transported to Korriban for training as a Sith, since their Force-sensitivity greatly impressed those who discovered them. During this period, the Sith Order had made the decision to permit non-Imperials to train as Sith Inquisitors. Upon reaching the academy on Korriban, the newly named acolyte was assigned to Overseer Harkun, who was instructing other non-Imperial Sith, whom he held in contempt, especially former slaves. The overseer openly displayed his disdain, openly discriminating against the acolyte in favor of another acolyte in the group, a pureblooded Sith named Ffon Althe. After a brief introduction upon the acolytes' arrival, Harkun assigned the acolyte their first quest: to travel into Ajunta Pall's tomb and be tested by Lord Spindrall.

After eliminating several K'lor'slugs and tomb raiders along the way, the acolyte eventually encountered Spindrall, who tested the young acolyte by dispatching his own six acolytes to attack. The young acolyte quickly defeated them all, passing the test and subsequently exiting the tomb. Having succeeded, the acolyte returned to Harkun, who was awaiting them in the Sith Academy, but not without first meeting an assistant overseer called Markan, who introduced the acolyte to some core Sith tenets before redirecting them to Lord Samus for further training.

Upon returning to Harkun's office, Harkun executed an acolyte, Kory, for her weakness and failure to meet her potential before assigning the acolyte to a quest in the academy's jails, which Lord Zash herself had requested for them. In the jail, Inquisitor Zyn instructed the acolyte to interrogate a weak acolyte named Alif; they succeeded, getting the answer that Zyn wanted from Alif. Harkun then proceeded to assign both the acolyte and Ffon to different trials of intellect. While Ffon's task was less dangerous, merely having to translate some ancient texts, the acolyte's task was to travel to Marka Ragnos's tomb and recover an ancient holocron. The acolyte fought through hordes of Tuk'ata and Shyracks to reach the objective but succeeded nonetheless, retrieving the holocron through the use of Force lightning.

Upon returning to Harkun, he was both surprised and displeased that the Acolyte had survived and was quick to send the acolyte on another difficult task. At the same time, the acolyte was gaining renowned praise for the feats they performed in the tombs.

The acolyte was dispatched by Harkun, at Lord Zash's request, to retrieve a text in Tulak Hord's tomb as part of Zash's research on the ancient Dark Lord's artifacts. As before, they succeeded in this task, retrieving the archived text. Upon returning to the academy, the acolyte was met by Lord Zash herself, who complimented their success. She told the young acolyte that she had great hopes and that the acolyte was likely to become the apprentice she was looking for.

The acolyte then met Harkun and delivered the artifact to him in his office. The overseer refused to believe that they had met Zash and sent them to the academy's training facility. Upon arriving in the facility, the acolyte was met by two of Harkun's other students who had been assigned to slay them in exchange for permission to leave and go home. The acolyte, however, was far too strong and easily killed the other two.

Realizing the assignment had been a trap, the acolyte returned to Harkun, who then assigned their final trial. He wanted the acolyte to retrieve an ancient map from Naga Sadow's tomb, which first required releasing a sentient beast called a Dashade. Harkun, in an attempt to rig the trial in Ffon's favor, sent him onto the trial while the acolyte was away. However, Zash interrupted the conversation and gave the acolyte the translated text that was previously retrieved from Tulak Hord's tomb. This information, which was vital to reach the ancient map, gave the acolyte a great advantage over Harkun's favored student, Ffon.

The acolyte breached the tomb, destroying the droid guardians protecting it, and released the Dashade. They soon learned that the Dashade was Tulak Hord's renowned, ancient shadow assassin named Khem Val. Upon release, the powerful creature immediately attacked the acolyte, but was ultimately defeated. In accordance with Dashade tradition, he pledged loyalty to the one who had bested him, giving the acolyte a powerful servant and companion. They continued on, defeating many droids in their path and even an ancient beast called a terentatek before recovering the ancient map.

The acolyte delivered the ancient map to Harkun, who had been arguing with Ffon that getting the map was impossible. The overseer was quick to snatch the map out of the acolyte's hands and give it to Ffon just as Lord Zash appeared. Zash, seeing the map now in Ffon's hands but knowing it wasn't he who recovered it, asked him to tell the truth. Ffon, fearing the consequences of lying to a Sith Lord, told Zash the truth and she killed him with Force lightning, and instructed the acolyte (Harkun's last surviving charge) to meet her in her office. The acolyte complied and Lord Zash accepted them as her new apprentice, telling the young Sith to meet her next at the Empire's capital of Kaas City on the planet of Dromund Kaas. Here, her new apprentice could develop their skills further. Firstly, however, she gave the young apprentice her old lightsaber as a gift.

While preparing to leave the academy and travel to the capital, the apprentice was met by another Sith apprentice, Ortosin, who brought an ultimatum from his master, Darth Skotia, Zash's superior. The apprentice refused to answer the ultimatum and a duel ensued, in which the apprentice killed Ortosin and the two thugs that accompanied him. The apprentice then departed to the Imperial Navy's headquarters, a massive space station called Vaiken Spacedock. There the apprentice met Overseer Kryos who helped the new apprentice decide which path to take: the Sith sorcerer or the Sith assassin.

Upon their arrival to Dromund Kaas, the apprentice was received by Darth Skotia himself and his two Trandoshan bodyguards, who threatened the young apprentice yet again, also telling the young apprentice to warn Zash that he holds the key. After leaving the spaceport the Apprentice completed several tasks assigned by Imperial officers who were having numerous troubles with slave rebels, deserters and the planet's own creatures.

The apprentice then reached Kaas City, the capital, and traveled to the Imperial Citadel where Zash awaited the Apprentice at her office. The apprentice immediately told her about Skotia's warnings and she revealed her plan to have the apprentice assassinate the cyborg Sith Lord by first exploiting his cybernetics' weaknesses. She then told the apprentice that the first step was to discover what Skotia was hiding and sent the apprentice on a mission to investigate and extract information from Skotia's former slaves who had now rebelled.

The apprentice succeeded and then infiltrated Darth Skotia's bunker. There, the Apprentice slew Skotia's guard including many Sith and even one Sith Lord, Ogathu, before retrieving a relic that controlled Skotia's Trandoshan bodyguards.

The Apprentice then returned to the Citadel and gave the relic to Lord Zash. Zash, knowing controlling the Trandoshans wouldn't be enough to defeat Skotia, sent the Apprentice on one more mission to retrieve a weapon that could destroy cybernetics noting that Skotia was mostly a cyborg and it would be effective against him. The weapon had been created by a scientist named Dorotsech who was being held captive by the rogue Sith Lord Grathan.

The Apprentice infiltrated Grathan's base and after killing everyone that stood in the Apprentice's path, the young Sith discovered Dorotsech who gave the Apprentice the weapon's location. The Apprentice then retrieved the weapon but not without killing Dorotsech first, leaving no witnesses for what had happened in Grathan's estate. When the Apprentice returned to Zash she decided her apprentice was ready and finally assigned the young Sith to kill Darth Skotia.

The Apprentice met Darth Skotia in his office. Knowing that they needed to get close enough to use the anti-cyborg weapon, the Apprentice used the Trandoshan relic to turn Skotia's bodyguards on him but Skotia easily killed them, stating that they were only for show. Darth Skotia then proceeded to attack the Apprentice, but the latter used the Cybernetics weapon on him. The weapon didn't kill Skotia but weakened him enough for the Apprentice to engage him in a duel. With his dying breath, Skotia warned the Apprentice that Zash would turn on them too. As the cyborg collapsed on the floor, the Apprentice promised to face Zash when the time came.

The Apprentice then went to the cantina, where Lord Zash was contacted by Darth Thanaton who accused her of slaying Skotia. Zash, having a concrete alibi, refused such accusations and was promoted to the Darth title in front of the Apprentice. The Apprentice then returned to Skotia's -- now Zash's -- former office, where Lords Kirnon and Calaverous were investigating the scene of the murder. The Apprentice was asked how Darth Zash had slain Skotia; the Apprentice replied that she didn't, the young Sith had done it themselves. No one believed them, however.

Eventually sent to the Dark Temple on Dromund Kaas by Zash, the Sith apprentice discovered ancient roots to a Sith Lord, a one-time friend and greatest enemy of the ancient Dark Lord Tulak Hord, Aloysius Kallig. The ghost of Kallig recognized the Inquisitor to be of his bloodline and the means to restore his family name to greatness. He warned the Inquisitor that the Sith play an endless game of treachery, a game his heir must win. He advises to beware the master and apprentice and never to be taken by surprise.

Also while at the temple, the Apprentice found a relic of Tulak Hord captured millennia earlier by Kallig before his death. After learning of the Apprentice's ancestry and recovering the artifact, they ventured back to Darth Zash and learned that many other such artifacts were hidden around the galaxy. The Apprentice was then given the task of finding these artifacts on Balmorra, Nar Shaddaa, Tatooine, and Alderaan.

Darth Zash instructed the Apprentice to recover an artifact sealed in Vault 305 on Balmorra. The contact on Balmorra was Major Bessiker. He and his assistant revealed that the vault was converted to a toxic waste storage facility and was overrun by colicoids. The Apprentice had to synthesize a colicoid serum which provided immunity to the toxic waste inside Vault 305. The first step was searching the records of Balmorran scientists who engineered the colicoids to be resistant to the toxic waste and that allowed them to even feed on it. After learning the data that described how to create the serum, Apprentice had to find Iannos Tyrek, who was the only person with expertise to produce it. After Tyrek was brought back to base, Bessiker refused to produce the serum unless the Apprentice first helped him free his son Hiran who was recently captured by the Republic. The Apprentice didn't take the extortion lightly but eventually agreed to help him. When storming the prison on Gorinth Plateau, Hiran was found in one of the cells. He was a Sith himself and revealed that he was seeking some unknown weapon mentioned in the Sith holocron he held. The Apprentice wanted the weapon and killed the fellow Sith as a result. Upon returning to the base, Major Bessiker was furious and attacked the Apprentice. The Apprentice was forced to kill the Major and promote his assistant to his position. The assistant ordered Tyrek to produce the serum which was used to give immunity to toxins inside the vault. As a result the Apprentice successfully recovered the artifact.

The third artifact was held by a Sith Lord named Paladius on Nar Shaddaa. Paladius manipulated and exploited the poverty of the Nar Shaddaa population to form a personal cult. The Apprentice first met with Destris Veran and Rylee Dray, former followers of the cult who were promised to be given control of the cult in exchange for their assistance. The Apprentice decided that the best way to weaken Paladius was to draw his followers away from him. The first step was to build up the Apprentice's reputation by eliminating the notorious Krayts leaders. The next step was to demonstrate the Apprentice's "immense powers" to Paladius' followers which would sway them away from him. The plan was to produce quakes beneath the ground by an explosion. The detonator was obtained from Gord Madel. After that, the Apprentice showed up at Meridian Hall where Paladius rallied his followers and was giving them a speech by hologram. During the speech, the Apprentice mocked Paladius and told the gathered followers to witness the Apprentice's own miraculous abilities, using the detonator to produce an enormous groundquake. The followers started to worship the Apprentice, despite Paladius' attempts to convince them that it was a fraud. Shortly afterwards, Paladius contacted the Apprentice and offered the artifact in exchange of leaving him in control of the cult. They met in his headquarters where he tried a double-cross by stripping the Apprentice of the ability to use the Force. Nevertheless he was defeated in lightsaber combat. The Apprentice then recovered the artifact and took over the control of his cult.

During the search for the artifacts, Kallig interrupted his descendant. He was suspicious of Zash's intentions and wanted the Apprentice to be prepared. Recently, he discovered that his old Sith mask was in the possession of Lord Khreusis. He tasked the Apprentice to recover it. The Apprentice found Lord Khreusis on Korriban and slew him to take the mask as their own.

The next artifact was in hands of pirates who found a refuge on Tatooine. The Apprentice was tasked to find Andronikos Revel, who was the leader of the pirate crew before his first mate, Sylas Wilkes, betrayed him and took his favorite blasters. Seeking revenge, Andronikos helped the apprentice find his old first mate through his former girlfriend Casey Rix, who was also part of the crew. They found out that Wilkes too was betrayed by the crew, who then took the artifact, as well as Andronikos' blasters, and went into the dune sea. The Apprentice followed them and found logs which indicated that the pirate crew was driven insane by the artifact's power. The artifact was recovered from the body of one of the pirates. At that point, Andronikos joined the Apprentice's crew.

The last artifact was in possession of House Organa on Alderaan. The Apprentice met with Elana Thul who was helping during the mission on Alderaan. By gathering some information, it was revealed that the artifact was secured in Elysium vaults and the key to the vault was in the hands of Jedi Master Nomar Organa. By breaking into House Alde's library and searching through old records, the apprentice discovered that he and Rehanna of House Rist were once in love but Nomar cancelled the marriage to become a Jedi. By manipulating Rehanna, the Apprentice managed to lure Nomar into coming to Alderaan where he was killed. The key was taken from his body and the artifact was stolen from the Organa's in the Elysium.

Kallig contacted his descendant once again. This time, he wanted the Apprentice to claim his old lightsaber, which was given to Jonas Escalus for keeping. The last descendant of Escalus at that time was Mila Escalus, who was working on Nar Shaddaa. The Apprentice tracked her down to one of the casinos. She revealed that her late father gambled the lightsaber to a criminal named Gyl Rosen. The Apprentice went to meet with Gyl but he refused to give away the lightsaber. He was then killed and the lightsaber was reclaimed.

After acquiring all of Tulak Hord's artifacts, Darth Zash asked the Inquisitor to return to the Dark Temple on Dromund Kaas to begin the ritual.

Taking Khem back to the Dark Temple, the Inquisitor discovered that Zash had aged rapidly from increased exposure to the dark side, barely kept at bay by her rituals. Now, she sought to use Hord's artifacts to forcibly take her apprentice's body. But before she could complete the ritual, Khem interrupted. Though her body died, Zash's spirit wound up in Khem's body. Furious at her apprentice's betrayal, Zash threatened to use Khem to exact her revenge. However, Zash discovered that because of the Dashade's bond to his master, she too was bound to serve her own apprentice. Worse, she had to fight Khem for dominance of his body.

Shortly afterward, Darth Zash's apprentices, including Corrin and Kaal, arrived and noticed the body of their master. Kaal accused the Inquisitor of murdering Zash and attacked. Corrin quickly broke up the fight and explained that Zash had a dream that consisted of the Inquisitor killing the master and leading the Sith to glory. Zash's apprentices then dedicated their loyalty to the new Sith Lord and bowed.

Despite inheriting Zash's power structure and the mantle of Sith Lord, this triumph would be short-lived. Darth Thanaton, a representative of the Dark Council and a firm believer in tradition, cast Lord Kallig into the tomb of Darth Andru, fully expecting his adversary to fall prey to the deceased Sith Lord. Only Aloysius's prompt action averted this fate. To bolster his strength for the impending confrontation with Thanaton, Aloysius directed Kallig to the tomb of the Sith Lord Ergast to master the Force walk, a ritual capable of binding Force ghosts and harnessing their power. After subduing the spirits of both Ergast and Andru, Kallig returned to confront Thanaton, yet the Dark Lord proved to be the stronger opponent, seemingly killing Kallig. Fortunately, the two ghosts shielded Kallig from death, and Zash's other apprentices rescued their new Master before Kallig's body could be disposed of.

Needing more power before confronting Thanaton, Kallig journeyed to Taris in search of another ghost, Kalatosh Zavros. After acquiring the ghost, and a new apprentice named Ashara Zavros, Kallig intercepted a distress signal from Quesh, indicating that Zash's apprentices had absconded with the key to Thanaton's private meditation chamber. Kallig successfully obtained the key but was unable to rescue the apprentices. Acting on Zash's counsel, Kallig made his way back to Korriban to select a new apprentice, thereby maintaining their position within Sith society. Kallig chose to observe the latest group of slaves being overseen by Harkun. Kallig held great expectations for the Kaleesh, whom Harkun referred to as Xalek.

Kallig traveled to Hoth after Andronikos Revel informed Kallig of rumors of a ghost on the frozen planet. Upon arriving on Hoth, Kallig encountered Imperial Reclamation Service officer Talos Drellik. When the Sith Lord encountered Drellik, he was searching for a rumored hidden temple in The Bitter End. After encountering the Force ghost of Horak-mul, who was inhabiting the body of an Ortolan, Kallig was instructed to desecrate the temple that Talos Drellik had been seeking, a temple dedicated to Naga Sadow. Despite Drellik's pleas to preserve the temple, Kallig destroyed every artifact within it. Pleased, Horak-Mul instructed Kallig to locate him aboard the Star of Coruscant, which had crashed in the Starship Graveyard. Refusing to enter into a blood pact with Horak-Mul, Kallig was ambushed by Kaleesh assassins. However, Kallig proved to be too powerful, and after overpowering the Kaleesh, Kallig bound Horak-Mul.

Kallig then went back to Dromund Kaas to confront Thanaton within his private meditation chamber. Kallig eliminated Thanaton's apprentice Rolan, but as the Lord turned to face Thanaton, the power of four ghosts spiraled out of his control. Kallig's body began to deteriorate, and the ghosts threatened to drive the young Sith into madness.

After returning to the ship, Zash embarked on a quest to discover a cure for her master. Shortly after, she discovered that Thanaton had replaced the journals of Darth Iratus and Darth Vilus as they had experienced similar issues. Kallig then broke into Thanaton's Private Library, used Force persuasion on the guard captain, and retrieved the authentic journals. The Sith discovered that Iratus had traveled to Belsavis and Vilus to Voss in search of a cure, but both had failed. As Zash and Ashara began to investigate the planets, Kallig went to Korriban to check on Harkun. The overseer was betting on the Gran acolyte, although Kallig still favored Xalek.

On Belsavis, Kallig followed Iratus's path in an attempt to heal the deteriorating body. There Kallig found an ancient Rakata Mother Machine and, in exchange for Kallig's DNA, the Rakatan Warden Gorshaa, helped recreate Kallig's body so that he could withstand the physical strain of using the ghosts.

Upon returning to the ship, Kallig received a call from Moff Valion Pyron, who proposed an alliance against Thanaton. He explained that to sway other Moffs to Kallig's side, they needed to demonstrate that Kallig was more deserving of leading the Empire than Thanaton. His solution was a fleet-destroying superweapon, codenamed Silencer, a project that Thanaton had abandoned, claiming that the Force was superior to any technology. All that remained to complete the weapon was a CN-12 chip, which was manufactured on Nar Shaddaa. He suggested that Kallig contact the Cult of the Screaming Blade, whose loyalty Kallig had secured as Zash's apprentice, in the hopes of obtaining the CN-12.

Returning to Nar Shaddaa, Kallig learned from the cultists that the CN-12 was in the possession of a trio of cyborgs known as the Veil, who would only speak with the Sith. Upon learning this, Kallig met with the Veil, who attempted to trade the chip for control of the cult. However, Kallig used a mind trick to force them to join the cult.

Kallig returned to their ship to report the success to Pyron, who then informed the Sith that Thanaton had ascended to the Dark Council, his predecessor having died under mysterious circumstances. This pleased Kallig, who knew that finally killing Thanaton would also earn his seat. Pyron added that the Dark Council shouldn't know and warned that the other Moffs may not be so eager to oppose a Dark Councilor. Kallig then asked Pyron as to his motives for opposing Thanaton. The Moff stated Sith tradition has held the Empire from crushing the Republic and he believes that Kallig would be far more suited to accomplish this than Thanaton. As Pyron signed off, promising to complete the Silencer, Ashara approached Kallig, reminding her Master that they cannot face Thanaton with the ghosts out of control and suggested they go to Voss.

Although Kallig's body had been healed, the young Sith's mind remained fractured. Upon docking at the Voss space station, the ghosts began to taunt Kallig for believing that an imaginary ritual could subdue them. Ignoring them, Kallig listened to Zash describe the planet Voss. It was apparently a utopia, governed by the Voss Mystics, who viewed the Force as a conduit for healing and visions. Healing rituals were rare and often forbidden. But before Zash could elaborate, Khem regained control. Kallig then decided to meet with an Imperial emissary, Athelis Kallis, in Voss-Ka.

Upon boarding the station to obtain transport to the surface, Kallig was approached by a Voss emissary named Sor-Nak, who declared that the Mystic Alor-Wan had foreseen that Kallig would destroy the Voss way of life and demanded that the Sith Lord turn back. Kallig refused to retreat after enduring so much hardship, so Sor-Nak departed, stating that Alor-Wan had foreseen that he would not resort to force and promised that he would find another means of persuasion.

Kallig met with Kallis and her partner, Rul Jophen, at the Imperial embassy. After being advised to avoid upsetting the Voss, Kallig explained their mission to Kallis, who suggested that the Sith Lord seek out the outcast dream-walker cult.

Kallig later arrived at the cult's enclave and, with the permission of their leader, Asa-Ku, underwent their initiation ritual in order to learn their mind-healing ritual. The ritual caused Kallig to enter the dream world, where the ghosts disguised themselves as familiar figures in Kallig's life, whom the Sith Lord had to battle. Upon returning to the waking world, Asa-Ku instructed Kallig to go to the Shrine of Healing, providing an insignia that would grant the Sith Lord entry into the cult's chambers where the mind-healing ritual could be learned.

Upon entering the Shrine, Kallig was addressed by a disembodied voice, another Force ghost, this time a Voss named Mar-Da, who was the first and last dream-walker, who stated that the mind-healing ritual was forbidden. As punishment for the ghost's defiance, Kallig bound Mar-Da and forced him to reveal that a dream-rock in the Nightmare Lands could defeat the ghosts bound to Kallig by turning them to flesh and blood, but only a Gormak could use it.

Subsequently, Kallig received a holocall from Kallis, announcing that a pair of Voss commandos was tearing apart her office. After returning to Voss-Ka and disposing of the interlopers, Kallig then had Kallis consult her research, confirming that the closest the Gormak had to Force-users were dream-walking shamans.

Journeying into Gorma-Koss, Kallig used dream-walking to communicate with a sympathetic Gormak named Hadrik, who was weary of the conflict between Voss and Gormak. As the shaman was imprisoned by the Gormak king, Jokull, for speaking out against him, Kallig rescued him in reality. Hadrik agreed to perform the ritual in exchange for passage offworld. They then traveled into the Nightmare Lands and dream-walked, where they found the dream-rock, containing the spirit of a Voss named Dal-Rin. Dal-Rin instructed Hadrik to use the rock on the "ghosts", whom he referred to as nightmares, in order to defeat the ghosts and heal Kallig's mind. The pair proceeded to use the rock to strip away the ghosts' disguises and bested them in combat one-by-one. Once all the ghosts were defeated, Kallig used the rock and was healed.

Upon returning to the space station, Kallig and Hadrik found Sor-Nak waiting for them, who declared that by taking a Gormak off Voss, his people will reject the Empire. To preserve Imperial interests, Kallig used a mind trick to make Sor-Nak forget Hadrik.

Harkun then contacted Kallig that the slave acolytes were in their final trial. Returning to Korriban to await the acolytes during their final trial, Kallig maintained high hopes for Xalek. At first the Twi'lek Seferiss arrived with a tablet in hand, however Xalek turned up and proceeded to kill Seferiss. This blatant disregard for Sith tradition upset Harkun, who decides to pass up Xalek for the next group. However, Kallig decided to make an exception for Xalek and used Force lightning to kill Harkun, taking in Xalek as their new apprentice.

Kallig then rendezvoused with Pyron's flagship, the Doombringer, on which the Silencer was mounted. Arriving on the bridge, Pyron proclaimed to Moffs Dolus and Graham that Kallig is the future of the Empire. Dolus expressed hesitancy to ally with Kallig, fearing that Thanaton will have their heads. Graham, on the other hand, was willing to whittle away the ancient Sith traditions which had yet to win them the war. Kallig promised that Thanaton would be dead soon, but Dolus said he would not be moved until that happens.

Pyron ordered Dolus to be silent, as the Doombringer jumped into hyperspace and Pyron explained their plan to use the Silencer. They then emerged out of hyperspace as a lone Harrower-class dreadnought was fighting off a small Republic fleet, which they would target with their superweapon as a test. He then turned to Kallig, who gave a speech to the Moffs about how the Empire had to change if they were to win the war. But, as they readied the Silencer to fire, they received a distress call from Darth Achelon aboard the Carnage, requesting immediate aid. Graham identified Achelon as a minion of Thanaton and advised firing the Silencer at him. Dolus warned that purposely firing on an Imperial vessel was as good as treason. Pyron argued that the Republic would destroy the Carnage and not using the Silencer will result in their destruction too, but deferred command to Kallig.

Therefore, Kallig chose to aid Achelon and fired the Silencer after letting him get to safety, saving Achelon's ship and destroying the Republic fleet. This showed the Moffs that the Empire was more important to Kallig than his power struggle with Thanaton. Impressed, Dolus and Graham agreed to an alliance with Kallig. In turn, Kallig instructed Pyron to see that their new allies receive a Silencer for their capital ships.

With Nox's victory and newly made allies in the Imperial military, Kallig now had a formidable powerbase Thanaton was forced to acknowledge. Thanaton soon called for a Kaggath on Corellia, an opportunity for one another to silence their foe once and for all. Thanaton put many resources towards shutting down Kallig's base of operations and fought the lower-level Sith Lord as much as the Republic defenders. However, Kallig still managed to get ahead using knowledge and power to avert disaster.

Thanaton finally challenged Kallig to a duel on Corellia, but when it became apparent that he would lose, Thanaton fled to Korriban to plead to the Dark Council for the former slave's execution. Unfortunately for Thanaton, the Sith Lord interrupted his speech before he could convince anyone. Curious to see why Thanaton was unable to destroy Kallig himself, the Dark Council allowed the two to duel again in front of them.

After one last struggle, Kallig proved they were the stronger Sith and unleashed the power of the Force ghosts to overcome Thanaton's Lightning Storm and brought Thanaton to his knees with the power of the Force. Beaten, Thanaton crawled to his fellow Dark Councilors, pleading for their aid, but Darth Mortis reached out with the Force and snapped Thanaton's neck, killing him instantly for breaking the rules of the Kaggath. With Thanaton's seat on the Council now open, Mortis offered his position to the young Sith. Darth Ravage protested, stating that Kallig, as merely a Lord, could not sit on the Dark Council, but Darth Marr silenced his protests, stating that Kallig had earned the right. In light of the reputation earned as a dark side master, Marr bestowed Lord Kallig with the title of Darth Nox, head of the Sphere of Ancient Knowledge, one of the twelve power-bases of the Sith Empire.

Afterwards, the newly christened Darth Nox returned to Dromund Kaas to enforce dominion upon those formerly of the Sphere under Darth Thanaton and gain their allegiance. As soon as they were all dismissed, the ghosts (except for Horak-Mul) pleaded to be freed, but Nox chose to keep them under bondage.

Eventually, as the war went on and new threats arose, Nox traveled to Rishi. The threat of the Revanites had drawn both Nox's attention to the planet and ire upon the Revanites. However, in the midst of ruining the Revanites' efforts, Nox was contacted by Moff Pyron. Pyron had been with searching for Revanite infiltrators within Nox's power base and was giving the Dark Lord an update on the search. Along with this, Pyron reported several situations that Nox needed to choose, including the status of the Silencer weapon and the recruitment of the Alzarians.

Lastly, Pyron realized Nox was on Rishi, and told the Dark Lord of their servant, Lord Veijel, who had been seeking an audience. Nox and their companion, Talos Drellik, met with Veijel, who had been sent to Rishi thirty years ago by Darth Arctis and tasked with finding the secret of immortality. Veijel told Nox that he had built arrays that were supposed to communicate with others in the Rishi dwarf galaxy and that the arrays had received messages from other beings, supposedly Sith, Rakata, and Gree ancients. Veijel inquired that the arrays and beings were waiting for Nox due to their messages relating to the Dark Lord's past. Per Veijel's request, Nox set out and examined each of the arrays.

At each machine, the phrase, "The Dark Lord's lifespan increases by one solar cycle" was repeated. When Nox reported this to Veijel he became enthusiastic. Veijel told how Thanaton and Arctis believed the Rishi Maze held the secret to immortality but he himself doubted. The Sith Lord asked for fleets and scientists and forces so that he could explore the dwarf galaxy and find the secret to immortality. Drellik reminded Nox that the search for immortality was never successful, emphasizing Zash's failed plan. Drellik also told Nox that the Dark Lord's resources should be used to help the Empire rather than this quest. However, despite Talos' warning, Nox granted Veijel's request in pursuit of everlasting glory and immortality.

During the Revanite crisis, Marr admitted to Nox that no majority council vote would not be needed for military action, just theirs. After the battle with Revan, Darth Marr stated that Nox was the only Dark Council member that he could trust. This effectively meant that Marr was sharing his control over the Empire with them until Marr's death and Nox's disappearance.

Around 3632 BBY, when the Eternal Empire conquered the galaxy, Darth Nox was still considered missing. In their absence, Nox's crew was dismantled and separated, going off on their own. Talos Drellik returned to the Reclamation Service and was sent to investigate an ancient power on Yavin IV. Xalek was promoted to Sith Lord, but when his father's burial site on Ilum was disturbed by Republic miners, he vowed revenge, believing that his father would no longer be able to attain godhood. Ashara was condemned by the Jedi and couldn't trust the Sith, so she spent the years travelling the galaxy to aid others. When Darth Nox went missing, Andronikos spent his time searching for Nox by raiding ships, and at some point was almost killed by Vaylin during her time as Empress. Khem Val moved from planet to planet devouring any Force-sensitives he found, eventually settling on Ossus.

Darth Nox, a master of manipulation, employed both cunning and ambition to undermine allies and adversaries alike. A prime example of Nox's manipulative prowess was their successful manipulation of Ashara Zavros, leading her to open a Sith holocron that initiated her transformation into a Dark Jedi, her abandonment of the Jedi Order, and her decision to become Nox's follower. Nox delved deeply into experimenting with long forbidden powers and didn't hesitate to develop dangerous yet scientifically advanced weapons of mass destruction in order to increase influence and seize authority. This demonstrates Nox's willingness to defy tradition, believing that the Sith Empire needed to adopt new methods and tactics to achieve victory, making Nox a dangerous and despised enemy not only to traditionalists like Darth Thanaton but also to the Jedi and the Republic.

Darth Nox derived great pleasure from the feeling of subterfuge during their political maneuvers, the very suffering of others and would often torture weak minions, prisoners and opponents for simple amusement. The Sith Lord electrocuted those who were defiant, and also killed a member of Nox's converted Cult of the Screaming Blade for just approaching the Sith Lord. Darth Nox also did not take kindly when being talked down to because of their history as a former slave or their quick rise to power, yet this same history and power did impress some like Darth Decimus, the feared Dread Masters and even the spirit of Revan.

Even though Darth Nox was corrupted, the Sith Lord also showed respect to some individuals and cultures such as Nox's apprentice Xivhkalrainik and the Kaleesh. When Xivhkalrainik told Nox of his culture, Nox showed interest in it and asked questions about the culture. As such, Darth Nox cared little about one's standing in terms of one's species, valuing and respecting those who were useful and loyal to the young Sith Lord and to the Empire, a trait that was rare in the Sith Empire and was shared by Darth Nox's ally, Darth Marr.

Despite Darth Nox's amoral nature and ambition to achieve power, Darth Marr and others note that while the young Sith's methods are unorthodox, they serve the Empire's interests, not just Nox's. As stated by Darth Marr, they "serve the Empire in their own way" and has done far more than any other member of the Dark Council would have done in Nox's time on the Council. They are also capable of kindness and compassion as they could choose to spare someone rather than torture or kill them.

Darth Nox possessed the capacity to channel the Force and mold it to suit a range of purposes, including the subduing, stunning, or elimination of adversaries. Nox was also an astonishingly proficient user of Force lightning. The young Sith was a proficient lightsaber duelist, utilizing either a standard lightsaber or a double-bladed lightsaber in combat.

Proof of Darth Nox's power was demonstrated when Khem Val, the former servant of Tulak Hord, became one of their companions despite many powerful Dark Lords avoiding Khem Val while imprisoned in stasis due to the Dashade's Force immunity and record for killing and devouring even some of the most powerful Force-sensitives.

The Sith apprentice, Nox, swiftly ascended to the Dark Council, eventually becoming a Sith Lord of considerable power. Nox's command over the dark side was so great that they could easily overcome a Dark Council member of Darth Thanaton's stature. In their confrontation with Thanaton, Nox showed proficiency in using Force deflection to defend against Force lightning, effortlessly swatting away Thanaton's attacks. Telekinesis was also among the young Sith's abilities, exemplified by Nox flinging Thanaton across the Dark Council chamber. Furthermore, Nox used telekinesis to halt Darth Thanaton's lightsaber strike, forcing the experienced Dark Lord to his knees. Nox also demonstrated the ability to utilize Force choke.

Darth Nox possessed exceptional skill in the "innate gift" of Sith sorcery, particularly the ancient Force walk ritual. This ritual allowed them to draw power from numerous Sith spirits, dramatically amplifying their dark side abilities. This immense increase in power granted by Force Walk was sufficient to overwhelm a Sith Lord as formidable as Darth Thanaton. Aloysius Kallig explained that Nox possessed a unique "pull among ghosts", enabling them to sense spirits from afar and evoke long-dormant emotions. Nox also skillfully employed the Force Storm, using it in battle against various opponents. The young Sith could also use Force drain, using it to drain opponents while invigorating themselves and allies.

Similar to the Emperor's Wrath, Darth Nox possessed extraordinary willpower, allowing them to resist the spirits' attempts to induce madness, the Dread Masters' fear-inducing powers, and even the Sith Emperor's dominating influence.

Darth Nox had a comprehensive understanding of numerous galactic languages beyond Basic. Having interacted with individuals from diverse species, the young Sith achieved fluency in Dashadi, Binary, Huttese, Twi'leki, Ortolan, and Rodian.

This article details the storyline of the Sith Inquisitor player class featured in Star Wars: The Old Republic, a video game developed by LucasArts and BioWare. Given that the character's path is determined by the player, there isn't a definitive canonical portrayal of this individual; therefore, the article refers to the character using gender-neutral pronouns. The choice between becoming a Sith assassin or a Sith sorcerer is left to the player. The standard species options for Kallig include Human, Cyborg, Zabrak, Sith Pureblood, Twi'lek (exclusive to Imperial classes), and Rattataki. If Kallig isn't Human, Cyborg, or Sith Pureblood, they may encounter anti-alien prejudice, though this has a limited effect on the story. If Kallig is either a Twi’lek or a Zabrak, they may encounter unique dialogue options specific to their species. During the mission titled "Preparations", if Kallig is a Zabrak and asserts their Countenance as their birthright, Lord Khreusis will reject this claim, referring to them as a "Zabrak criminal". Conversely, if Kallig is a Twi’lek and selects the same option, Lord Khreusis will label them a "Twi’lek slave". During the mission "Scouring the Wastes", Talos Drellik will offer an apology to a Twi’lek Kallig after using the Twi’lek species in a metaphorical context.

Euan Morton lends his voice to the male Kallig, while Xanthe Elbrick provides the voice for the female Kallig.

Upon completing the main storyline for the Sith Inquisitor class, which concludes with the player defeating Darth Thanaton, Darth Marr bestows the title of Darth upon the player. The name accompanying the title varies based on the player's alignment: Players renowned as masters of the dark side receive the title Darth Nox; a neutral reputation results in the title Darth Occlus; and players known for serving the Empire (light side) are designated Darth Imperius. Regardless of the title earned through the storyline, the Darth title precedes the character's chosen name if the player chooses to display it in-game. In dialogue, the Inquisitor is typically addressed as "Dark Lord," and occasionally by the name conferred by Darth Marr.

Players who begin the Sith Inquisitor class at level 60 and bypass the preceding story quests will automatically be addressed as Darth Imperius. However, the game still assumes that Dark side choices, such as the killing of Koth Vortena, were made.