Exar Kun trained under Jedi Master Vodo-Siosk Baas four thousand years before the battle of Yavin. However, he was lured by the dark side of the Force. He traveled to the Tomb of Freedon Nadd. Lead by the spirit of the ancient Sith Lord, Exar traveled to the Sith Mausoleums of Korriban. There, he fully embraced the dark side. He then journeyed to Yavin IV and found a legion of Massasi, servants of the dark side, waiting for the coming of a new Dark Lord. After obliterating Nadd's spirit, Kun made Yavin the Sith's new headquarters. When another fallen Jedi, Ulic Qel-Droma, came to Yavin, Exar intended to kill him. However, the ghost of the Sith Lord Marka Ragnos appeared and told Kun that he was now the new Dark Lord of the Sith and named Droma his apprentice. Now emblazed with a Sith tattoo on his forehead, Kun swayed more Jedi Knights to his cause. On Coruscant, Kun engaged in an epic duel with his former master, which ended with Baas lying dead on the senate floor. To celebrate this victory, he ordered the Massassi to build new temples dedicated to his glory. He was on top of the galaxy. However, Ulic, feeling guilty, had revealed the location of Kun's army. A Jedi taskforce, including the promising Jedi Knight Revan, was sent to Yavin. Kun was killed in the strike. But his spirit lived on. He had left a night beast, fueled by inprisoned Massassi children, it protected his tomb, preserving his spirit inside of the walls of the temple. He lingered there for four thousand years. Several years after the Battle of Endor, Jedi Master Luke Skywalker set up his Jedi Academy on Yavin. Kun gave one student, Gantoris, enough knowledge to challenge Skywalker, but his alignment with the light prevented him from killing him, the whole thing being veiwed as a sparring match. Gantoris attempted to kill him, but Kun destroyed him. Kun struck gold, however, with Kyp Durron, the most promising student in the academy. However, Skywalker and his students combined skill obliterated his soul, ridding the galaxy of him forever.