Set Harth was a male Human Dark Jedi who operated in the decades following the Ruusan Reformations within the Galactic Republic. He began his journey as a Padawan in the Jedi Order, but his Master, Aru-Wen, met his end during the final days of the Ruusan campaign in the New Sith Wars. Following Aru-Wen's death in the final battle of the war on Ruusan, Harth underwent training with Master Obba from the Council of First Knowledge. Obba's deep interest in researching Sith artifacts sparked Harth's own fascination with the Sith, ultimately leading him to embrace the dark side of the Force. Subsequently, Harth left the Order and established himself on Nal Hutta, creating a mansion there and on other planets under various identities, to safeguard the dark side artifacts he managed to acquire.
In 980 BBY, Harth successfully obtained several artifacts that had been excavated on Doan. However, Sith Lord Darth Zannah tracked him down and defeated him, compelling him to become her ally as she sought to eliminate her own Sith Master, Darth Bane.
Working together, Harth and Zannah discovered that Bane had been captured and was being held at the Stone Prison on Doan. Zannah ventured inside to confront her master, leaving Harth to guard their transport. Nevertheless, Harth entered the prison himself and located the holocron of Darth Andeddu, which had been seized from Bane after the Dark Lord's capture. Harth then escaped the prison, but not before briefly encountering Zannah's apprentice, Darth Cognus, and began studying the method of transfer essence under the holocron's gatekeeper. By combining this ability with clone bodies, Harth managed to survive until at least the time of the Yuuzhan Vong War.
As a Force-sensitive Human, Set Harth was welcomed into the Jedi Order, where he underwent training in the ways of the Force under the guidance of Jedi Master Aru-Wen at the Coruscant Jedi Temple. When the Temple battlemaster, Jedi Lord Hoth, assembled the Army of Light from the holdings of the Jedi Lords throughout the galaxy, Harth's master left Coruscant to participate in the battles. Harth briefly accompanied him, giving in to his anger while fighting a warrior of Lord Kaan's Brotherhood of Darkness. Due to Harth's inclination towards violence, Aru-Wen instructed his Padawan to return to the Coruscant Temple while he journeyed to Ruusan to join the Army of Light for the final confrontation with Kaan. During the Seventh Battle of Ruusan, Kaan unleashed a thought bomb upon the Army of Light, resulting in the deaths of exactly 100 members selected to perish alongside Lord Hoth, including Aru-Wen.
Following the demise of his Master on Ruusan, Harth became a student of Master Obba. Collaborating with the Ithorian Jedi, Harth joined the Council of First Knowledge in their efforts to locate and secure all Sith artifacts scattered across the galaxy. As he received more and more assignments, Harth started to hoard the artifacts he discovered, eventually accumulating enough wealth to leave the Order and delve into the ways of the dark side.
Harth became aware of rumors regarding a Sith artifact that had survived the destruction on Ruusan. He located the artifact within an abandoned Sith armory on the Ruusan battlefields, where he fought a dark side warrior to claim it. Harth emerged victorious and obtained the artifact, which further corrupted him. Harth then established a mansion on Nal Hutta and initiated a search for other Sith artifacts.
One of Harth's searches led him to the palace of a Hutt slaver, where he encountered another Dark Jedi, Bal Serinus. They engaged in a duel that pushed them to their limits. Before they could conclude their battle, the Hutt slaver captured both dark siders. While imprisoned in separate cells, Harth and Serinus communicated through the Force. Harth vowed to protect Serinus from harm, but she suddenly rejected his telepathic contact, leading Harth to swear vengeance.
In 980 BBY, Harth journeyed to the planet Doan to retrieve recently excavated Sith artifacts. He coerced a Rodian bartender, Quano, to guide him to the miner who had unearthed the artifacts, Draado. As Draado attempted to rally the miners to revolt against the Doan Royal House in response to the recent assassination of their leader, Gelba, Harth ambushed them. The other miners were quickly eliminated, but Draado survived briefly due to the artifacts he wore. However, Harth managed to use Force choke to kill the miner, seize the artifacts, and return to Nal Hutta.
Upon Harth's return, Darth Zannah, the apprentice of Darth Bane, tracked him to Nal Hutta and, following a brief duel at Harth's estate, offered him the chance to become her apprentice. Realizing that refusal would mean death, Harth accepted. They traveled to Bane's home on Ciutric IV, where Zannah and Bane had resided, only to find that Bane had been captured by the Royal Guard of the Doan Royal House. Unbeknownst to Zannah and Harth, Princess Serra of Doan, who had ordered the attack, was actually Caleb's daughter. She sought revenge on Bane, whom she mistakenly believed had killed her father.
Zannah and Harth returned to Doan to rescue Bane from the Stone Prison, but he had escaped with the help of Serra's bodyguard Lucia, a former member of the Gloom Walkers under Bane. Zannah instructed Harth to guard her vessel, the Victory, before entering the prison, where she confronted Bane in a duel to claim the title of Dark Lord of the Sith.
However, Harth disobeyed Zannah and entered the prison, discovering and stealing the Holocron of Heresies, which had been taken from Bane. As Harth fled, he intended to steal a starship, the Stalker. Before he could escape, the ship's owner, the Huntress—the Iktotchi assassin who had captured Bane—arrived and challenged him. After a fight in the hangar where the Huntress gained the advantage, Serra—who hoped to eliminate both Sith Lords—initiated the Prison's self-destruct sequence. Harth then disabled two of the four ships in the hangar with his lightsaber and proposed to the Huntress that either they both should go free in their own ships or he would destroy both ships and they would be killed in the collapsing prison together. The Huntress accepted, allowing him to flee in his starship, taking the holocron with him. Soon after he began lessons from the holocrons gatekeeper on the dark side of the force, and the technique of essence transfer.
Fearing Zannah would find him on Nal Hutta if she survived the Stone Prison's destruction, Harth knew better than to go back to his usual location. Since he had other bases under false identities, there was no need for him to run aimlessly across the galaxy. With sole possession of Darth Andeddu's holocron, Harth had unrestricted access to its vast repository of knowledge. Committing himself to the holocron's gatekeeper, Harth agreed to train under Andeddu to eventually master the ability to transfer his consciousness into other bodies.
In time, Harth mastered this ability and contacted cloning specialists who could replicate his original body. For over a millennium, Harth repeatedly cloned his original body, typically discarding the clone bodies at age 30. Over the centuries, Harth amassed extensive collections of Sith artifacts hidden in caches throughout the galaxy, along with numerous starships and substantial resources. Harth became a legendary explorer, his continued existence suspected but unproven by the Jedi High Council as he continued to search the galaxy for dark side artifacts.
Due to Harth's desertion from the Sith Order, Zannah realized that taking him in as an apprentice had been a mistake. However, after she defeated Bane on Ambria, Zannah took on a more willing apprentice: the Huntress, who had taken the name of Darth Cognus before Zannah became the Dark Lord.
While in Harth's possession for some time, Andeddu's holocron was discovered on Korriban in 21 BBY by Sith Lord Darth Tyranus. It is unknown how he was parted from this relic, but it could not have been due to his final death as Harth was known to have lived past the Clone Wars.
During the war with the Brotherhood of Darkness, the Jedi High Council's strict recruiting policies were loosened, allowing less than ideal candidates to receive training. Set Harth was one of these exceptions and, though Harth was allowed into the Jedi Order his master, Aru-Wen, felt that his violent tendencies indicated a dangerous path and left him on Coruscant.
Harth continued to take these paths because of his arrogance and allegiance to himself. Even when faced with a situation as dangerous as Darth Zannah and the legacy of the Sith, he pulled off a betrayal that made him a legend.
Set Harth possessed considerable skill in telekinesis, hurling objects at his opponents to disrupt them. Upon falling to the dark side, he mastered Force Choke, Force Grip, and Force drain. He also demonstrated talent in telepathy, Battlemind, Force sight, and the mind trick, which he evolved into Force fear as a Dark Jedi. Before betraying Darth Zannah, he realized his full potential when he could expand his awareness, due to some early part of his training under Obba. He later learned how to transfer his essence into other beings, which he used to extend his life indefinitely and thus lived for more than a millennium after he acquired this power. This extended to his knowledge of Sith magic.
Harth practiced his own unique version of Ataru, as seen in his duel with Darth Zannah. However, the form exhausted him, giving Zannah an advantage. He was also adept at throwing his lightsaber, a move that nearly killed Zannah and the Huntress on Doan; both survived due to their precognitive abilities. Zannah spared Harth due to his skill and her need for an apprentice.
During his time as a Dark Jedi, Harth carried two blasters alongside his lightsaber to conceal his Force abilities: a GSI-24D disruptor pistol and a conventional blaster. He was proficient with these weapons, easily defeating numerous miners during his skirmish on Doan.
Set Harth is a character in Darth Bane: Dynasty of Evil, the concluding novel of the Darth Bane Trilogy, penned by Drew Karpyshyn.