During the time of the Great Galactic War, there existed a male Human named Harkun, who was a member of the Sith Order. On the Sith graveyard world of Korriban, Harkun underwent training as an acolyte. After his training was complete, he found himself under the supervision of the Sith Lord Zash within the Sphere of Ancient Knowledge at the academy. As the Cold War raged between the Galactic Republic and the reconstituted Sith Empire, Harkun had progressed to the position of an Overseer on Korriban, where he oversaw the training of acolytes, a brutal process designed to transform hopeful initiates into Sith Lords. Around the year 3643 BBY, Zash instructed the Overseer to gather a new group of students from the Empire's lower-class slave population, in order to discover an apprentice worthy of her tutelage. Despite his deep-seated xenophobia and classist beliefs, Harkun reluctantly obeyed, bringing six new acolytes from the slave pens to the academy for instruction and assessment.
Harkun secretly introduced the acolyte Ffon Althe, who had undergone advanced training throughout the Empire and possessed superior Sith skills compared to the newly recruited slaves, hoping to influence the selection process and maintain the dominance of high-born Sith. However, his plans were consistently thwarted by a young slave-turned-acolyte whose cunning and talent allowed them to overcome every challenge set by the Overseer. This led Harkun to develop a strong animosity towards this acolyte, and he actively plotted their downfall, even though Lord Zash held a favorable opinion of the student. As the training and evaluation period neared its end, with only Althe and Harkun's disliked acolyte remaining, Zash commanded the Overseer to send the surviving acolytes on a final mission to retrieve a star map, once owned by the ancient Sith Lord Tulak Hord, from a perilous tomb located on Korriban's surface. Harkun attempted to give Althe an advantage over the other acolyte, but Zash intervened, ensuring the success of Harkun's least favorite student.
As a consequence of his attempted manipulations, Harkun was forced to witness Zash execute Althe before claiming the other acolyte as her apprentice. Soon after, the Sith Lord and her new apprentice left Korriban, leaving Harkun to continue his duties as an Overseer at the academy. Several years later, following the death of Lord Zash and the subsequent rise of her apprentice to the rank and title of Lord Kallig, Harkun was once again tasked with gathering a new group of acolytes from which Sith Lords could choose an apprentice. Harkun dutifully fulfilled his responsibilities as Overseer, managing a class of six new students. Although the group was initially presented to the elder Sith Lord Darth Thanaton, he declined, allowing Lord Kallig to select an apprentice from the group. Harkun remained loyal to Kallig's interests, but he struggled to accept the ultimate triumph of another slave-turned-acolyte, the Kaleesh warrior Xivhkalrainik. Lord Kallig, impressed by the Kaleesh, refused to tolerate Harkun's objections and instead used concentrated blasts of Force lightning to kill him.
Harkun, a Human male, attained the position of Overseer at the Sith Academy situated on Korriban. During the era of the Cold War, Lord Zash assigned Harkun the task of evaluating a cohort of acolytes for the purpose of selecting a suitable Sith apprentice. Among these acolytes was an aspiring Sith Inquisitor – a descendant of the forgotten Sith Lord Aloysius Kallig – whom Harkun held in contempt due to their slave origins. Harkun actively supported the Sith Pureblood acolyte Ffon Althe and exerted every effort to eliminate the slave-born acolyte from the competition. This included dismissing the acolyte's legitimate achievements, bribing other acolytes to assassinate them, and assigning them tasks that were nearly impossible to complete.
Throughout these trials, Harkun intended for the initiates under his supervision to be eliminated, but the future Inquisitor consistently persevered. For the final challenge, Harkun dispatched Ffon ahead to locate the star map within the tomb of Naga Sadow. However, Zash, who favored the Inquisitor, intervened by revealing how to liberate the Dashade Khem Val from his confinement within the tomb, thereby granting access to the star map. Ultimately, the Inquisitor succeeded where Ffon had failed. Nevertheless, Harkun seized the map from the Inquisitor and presented it to Ffon, allowing him to claim credit for the accomplishment. Upon Zash's arrival to claim her new apprentice, she easily detected Ffon's deception and questioned him. Overcome with fear, he promptly confessed the truth. To punish Harkun for his attempt to deceive her, Zash executed Ffon, thereby claiming the Inquisitor as her new apprentice. This enraged Harkun, who threatened to harass the Inquisitor wherever they went, although this threat proved to be empty.
Some time later, the Inquisitor – now a formidable Lord of the Sith and the heir to the legacies of both Lord Kallig and Tulak Hord – returned to Korriban in search of a new apprentice to replace Corrin and Kaal, two apprentices who had been purged by Darth Thanaton. During this period, Harkun treated Kallig with the utmost respect and was reportedly less severe towards the new group of acolytes, even asserting that he was not responsible for any of their deaths. Harkun placed his bets on the Gran acolyte, but, much like Zash before her, Kallig's attention was drawn to one acolyte in particular: the Kaleesh known as Xalek.
After returning at various times to observe the progress of the acolytes, Harkun remarked that Xalek possessed a determined look in his eyes, which reminded him of Kallig. However, it seemed that they were both mistaken when the Twi'lek acolyte Seferiss appeared, but Harkun was proven wrong again when Xalek shortly appeared afterward. Xalek then murdered Seferiss, which angered Harkun as it was a blatant disregard for Sith tradition and went against the academy rules. Kallig tried to reason with Harkun, but when it was quite clear he still remained defiant, Kallig released a bolt of Force lightning and killed Harkun.
Harkun possessed a distinctive physical appearance, characterized by dark brown hair, light blue eyes, freckles, a goatee, and a tattoo located near his right eye. Harkun exhibited politeness towards his superiors, Sith Purebloods, and individuals of high-ranking heritage. Conversely, he displayed open rudeness and cruelty towards slaves, aliens (excluding Sith), and those he deemed weak. This was evident when he executed Kory after she was deemed unworthy by Spindrall. Despite his apparent disdain for the Sith Inquisitor Kallig, he permitted him to continue his training, even when mocked for his attempts to insult him. This was likely due to Kallig's lack of apparent weakness. However, it is more probable that he refrained from executing Kallig out of fear of incurring the wrath of Lord Zash, who favored the Inquisitor. When Ffon Althe proposed assassinating Kallig in collaboration with the Overseer, Harkun suggested that it would be easier to make Kallig's death appear accidental if it occurred within one of the tombs, rather than in his office.
Harkun had the ability to use Force lightning, and he carried a single-bladed Sith lightsaber.
During the quest where Xalek becomes Kallig's apprentice, Harkun's fate is determined by the conversation choices made. The conversation choices depend on the answer to Harkun's protests regarding Xalek's murder of the acolyte Seferiss instead of finish the quest; most chains of dialogue will lead to Harkun walking away, declaring that he would inform Thanaton of what happened. If Kallig shows an apathetic disregard for the "tradition" of executing slaves guilty of murder ("I don't care" option) or tells Harkun that his "defiance is foolish and misplaced" ("Don't protest"), Harkun will state his concern that the Empire will fall "if the rules of subterfuge and skill give way to blind murder", giving three options: Either simply taking Xalek and leaving, Force-persuading Harkun that there was no murder and giving up his lightsaber to the apprentice, or killing him with Force lightning. If Harkun is spared, he will reappear near the end at the Sphere of Ancient Knowledge, where he will be one of those servants that bow before Kallig after the latter is seated on the Dark Council.
He will also send a message to the Hunter or Cipher Nine if either one completed the misson "Dreams of Korriban" on Hutta.