Eshkar Niin, an Iktotchi individual, held membership in the Imperial Knights. This Force-sensitive Order displayed allegiance to Emperor Roan Fel of the Galactic Empire. Progressing to the rank of Master, Niin became the mentor of Antares Draco, imparting strategic and philosophical knowledge while instructing the Human in the ways of the Force. Subsequently, Niin broke his Imperial Knight oaths and abandoned the Order. He launched an attack on Empress Elliah Fel, resulting in her death, but Draco, dispatched by the Emperor to eliminate him, ultimately defeated him. Draco presumed Niin to be deceased, but the Iktotchi survived, aligning himself with Darth Krayt's Sith Order and assuming the identity of the Sith Inquisitor Darth Havok. In 130 ABY, Krayt's Empire took control of the galaxy from Fel. Seven years later, a Sith group captured Fel's daughter, Marasiah, transporting her to Coruscant, the galactic capital. From there, Havok moved her to Korriban, the Sith planet, beginning her torture in an attempt to extract vital secrets about her father.
During breaks in the interrogation, Draco arrived to undertake a mission aimed at her rescue, staying behind to provide her with time as she fled the planet. Havok confronted his former apprentice, defeating him in a lightsaber duel before imprisoning him deep within the planet's dungeons. Havok then subjected Draco to intense torture, hoping to uncover Imperial secrets, and ultimately exploited Draco's affection for Marasiah to coerce him into revealing the existence of a Jedi Hidden Temple on Taivas. Subsequently, Krayt's forces attacked the temple. However, the Jedi and their allies evacuated, later launching a counterattack on Coruscant. Krayt met his end, and his Sith trooper army, connected to his will, descended into madness. Havok, along with other Sith, escaped from the deranged troopers on Korriban and fled the planet. Havok then met with Darth Nihl, his new Master. Under Nihl's command, the Sith went into hiding.

Before 137 ABY, Eshkar Niin, an individual of the Iktotchi species, was a member of the Imperial Knights, a group of Force-sensitive individuals whose purpose was to safeguard Emperor Roan Fel and uphold his Empire. Niin achieved the rank of Master within the Order, also serving as the mentor of Antares Draco. He provided training to the young Human, preparing him to become a Knight of the Empire. During his time as an Imperial Knight, Niin created a holocron, recording some of his teachings within the device. Ultimately, he violated his Imperial Knight vows and deserted the Order, leading the Emperor to dispatch Draco to kill him.
In the meantime, Niin located Fel's wife, Empress Elliah Fel. Both pursuits reached their climax atop a city rooftop filled with skyscrapers, leading to a three-way lightsaber duel that erupted. Both Draco and Elliah pleaded with Niin to cease his attack on the Empress, but he ignored their appeals. He used the Force to shove Draco away before striking Elliah down. Draco immediately responded, and at the duel's conclusion, he believed Niin had perished. Niin had, in fact, survived, but he allowed his former apprentice to continue believing in his death. The Imperial Knights, therefore, believed Niin, the only member of their order to ever abandon his vows, was dead.

After his departure from the Imperial Knights, Niin became a member of the One Sith, becoming both a Sith Lord and a Sith Inquisitor serving Darth Krayt, the Dark Lord of the Sith. He adopted the name Darth Havok, abandoning his previous identity. In 130 ABY, Krayt seized galactic control from Emperor Fel. Seven years later, Marasiah, Fel's daughter, was captured by a group of Sith who ambushed Imperial Knights on Agamar. She was transported to Coruscant, the galactic capital and the center of Krayt's Empire. Darth Wyyrlok, who had governed the Empire since his attempted assassination of Krayt and subsequent seizure of the throne, ordered Havok to take her to Korriban, the Sith world.
Immediately after Marasiah exited the starship of her escort, Moff Rulf Yage, Havok approached them on their landing platform, concealing his identity from Marasiah with a hood. Despite protests from Imperial Regent Morlish Veed, Havok took the prisoner away from Yage and brought her to Korriban. Once there, Havok chained Marasiah up in the Chambers of Persuasion and began to torture her with Force lightning, hoping to glean secrets about her father's Empire-in-exile. She was resistant, however, prompting Havok to remove his hood and reveal his identity. Marasiah was shocked to see him alive, but shook off her surprise and telekinetically tossed a bowl of hot coals at him. Havok deflected the attack, but the distraction allowed Marasiah to seize his lightsaber with the Force and place it beneath her chin, hoping to die rather than talk. Havok drew on the Force himself and took the weapon back. He then left the chamber to allow his prisoner some recovery time.
While Havok was away, Antares Draco, fellow Imperial Knight Ganner Krieg, and the Jedi Knight Shado Vao arrived at the chambers on a mission to rescue the Princess, and they freed her from her bonds. Draco remained on-world to allow his allies time to flee the planet in their escape ship, and Havok approached him as he was slaughtering a group of Sith. As they engaged each other in lightsaber combat, Darth Krayt, alive and well, projected his will across the galaxy. Both Havok and Draco were drawing on the dark side of the Force and felt his call. Havok offered Draco a chance to join the Sith, but when the Imperial Knight refused, Havok shocked him with Force lightning. Draco's presence was severed from the Force, and, defeated, he became Havok's prisoner.

Deep within Korriban's dungeons, Havok subjected Draco to excruciating torture, using the Force to lacerate his body with fragments of transparisteel. Draco refused to disclose Imperial secrets, declaring that he would rather die. Havok provided him with periodic rest in a bacta tank to ensure he remained alive long enough to reveal the information Havok sought. Having trained Draco in the ways of the Force, Havok understood Draco's weaknesses and crafted a Force illusion that transported his former apprentice back to the day of Elliah Fel's death. As Draco relived the duel, Havok appealed to his guilt, claiming he had been too weak to save her. Havok then projected another illusion onto his fellow Sith Lord Darth Talon, making her appear to be Marasiah Fel. He told Draco that Vao and Krieg had been killed during their escape from Korriban and that Marasiah had been recaptured, and Talon planted a kiss on Draco's lips to promote the deception. When Havok threatened to kill her if Draco did not tell him any valuable information, Draco lost his resolve and revealed the existence of a Jedi Hidden Temple on Taivas. Talon left to relay the findings to Darth Krayt, now back in control of the Empire, and Havok continued to torture Draco with Force lightning.
Talon delivered Draco to Krayt's nemesis, Cade Skywalker, whom Krayt hoped to entice into a confrontation. The Jedi Order and its allies gathered to defend the Hidden Temple from Krayt's forces, and there, the Dark Lord unleashed upon them his secret army of Sith troopers, dark warriors who were linked to his will. After the allies evacuated Taivas, they launched a counterstrike at Coruscant that saw Krayt die at Skywalker's hands. The Dark Lord's death saw Sith troopers across the galaxy go mad, and the Sith forces at Coruscant killed many of them before fleeing the capital. On Korriban, many Sith died at the hands of the insane troopers, but Havok and several others evacuated. Havok rendezvoused with Darth Nihl, Krayt's de facto successor, elsewhere in the galaxy, and Nihl instructed him to hide what was left of the Sith fleet. Krayt's Empire was fractured, and the Sith would now disperse themselves throughout the galaxy, infiltrate planetary governments, and wait for their opportunity to strike from the shadows.
Before joining the Sith, Eshkar Niin had brown skin and dark eyes; afterward, Darth Havok had fiery yellow eyes and Sith tattoos in black and red. As an Imperial Knight, Niin was recognized for his knowledge of strategy. He taught Draco a parable involving a fever wasp and a krayt dragon, informing his pupil that a small fever wasp could bring death to places where a large krayt dragon was unable. He also instructed Draco to always ensure that a slain opponent was definitely dead. Niin eventually left the Order, believing that the ways of the Sith were where his destiny lay. When he later dueled Draco on Korriban, he hoped to recruit his former student into the Sith's ranks rather than kill him. He struck Draco with Force lightning when the offer was refused. Havok was loyal to Darth Krayt, but he accepted Darth Nihl as his new Master following Krayt's death and addressed Nihl as "My Lord."
As a Sith Inquisitor, Darth Havok tortured information out of prisoners, inflicting pain on them until they wished for death. In addition to subjecting his charges to physical torture, he employed mind games in his interrogation, such as when he caused Marasiah Fel to doubt the honesty of Antares Draco. When he later tortured Draco, he used his knowledge of his former student's vulnerabilities and used Force illusions to appeal to Draco's guilt over not having saved Empress Elliah Fel. He eventually got Draco to talk by making him believe that Marasiah's life was in danger, but continued to torture his subject even after receiving valuable information.

Eshkar Niin held the rank of Master within the Imperial Knights, an organization reputed as one of the most skilled and dangerous groups of Force-users in the galaxy. The title of Master was exclusively granted to its highest-ranking members. However, after deserting the Order, he was defeated by his former student, Antares Draco, during a confrontation, and was presumed dead.
As a Sith Lord, Darth Havok demonstrated the capacity to use telekinesis to both counter and overpower Marasiah Fel's own telekinetic efforts, despite her being a fully trained Imperial Knight. He could also generate Force lightning, using it to defeat Antares Draco, an Imperial Knight Master. Havok displayed proficiency in creating Force illusions, employing them during the torture of his subjects.
Darth Havok was a creation of John Ostrander and Jan Duursema, conceived for the Star Wars: Legacy comic book series and making his initial appearance in its forty-eighth edition.