Mission to Vjun (Disciples of Ragnos crisis)

After the Imperial Remnant captured Rosh Penin, Jedi Master Luke Skywalker continued his strategy of deploying members of the New Jedi Order to various locations vulnerable to dark side energy exploitation by the Disciples of Ragnos and the Remnant. Specifically, he tasked Kyle Katarn and Jaden Korr to go to Vjun and investigate Bast Castle, previously one of Darth Vader's strongholds.

Upon landing their vessel, the Raven's Claw, near the castle, Katarn and Korr immediately encountered the dangers of Vjun's acid rain. Employing the Force to protect themselves, they soon confronted Imperial Remnant hazard stormtroopers. After defeating these soldiers, the two Jedi proceeded through the canyons towards the castle, engaging more Imperials along the way. At one point, after being suppressed by TIE Bombers, they located a nearby turbolaser. The duo then split up to reach the gun. Korr overcame several Imperials and Sith Cultists, but upon approaching the turbolaser doorway, he was confronted by a Reborn, a dark side soldier previously encountered during Desann's attack on Yavin 4. Following his victory over the Reborn in lightsaber combat and the destruction of the TIE Bombers, Korr rejoined Katarn, and together they managed to enter the lower levels of Bast Castle.

Once inside the castle's lower levels, Katarn and Korr discovered that the turbolift was inoperable. Much to Katarn's annoyance, they were forced to enter the garbage pit to gain access to the upper levels of the castle. They continued their ascent through Bast Castle by destroying several electrical conduits, using them to create a hole in the ceiling through which they climbed. After destroying a power generator to clear a path to the upper main hall, Katarn and Korr were once more separated by the resulting explosion. Katarn fell back to the lower levels, instructing Korr to proceed while he attempted to catch up.

Engaging more Imperials, along with assassin droids and lightsaber-wielding droids, Korr eventually reached one of the castle's main chambers, where the ruined remains of a Darth Vader statue lay toppled. After battling more New Reborn, Korr realized he was nearing his objective.

Upon entering the meditation chamber, where the Cultists were in the process of draining the dark side energy from the castle, Korr encountered Rosh Penin and the Kothos twins. Believing Penin to be a prisoner, Korr urged him to come along, but this proved incorrect. Penin, noticeably more subdued, revealed his turn to the dark side and his allegiance to the Disciples of Ragnos. Korr was then forced to duel his former friend. While Korr appeared to be the superior fighter, Penin was continuously revitalized by the energy transferred to him by the Kothos twins. Korr adjusted his strategy, eliminating the twins first before defeating Penin. As Korr stood over his fallen friend, Katarn entered the room. At that moment, Tavion Axmis appeared, revealing herself as Penin's new master and the leader of the Disciples of Ragnos. Restraining Katarn against a pillar with Force lightning and holding Korr captive, Axmis gloated over Katarn, mocking him for sparing her life during their last duel. When Korr threw his lightsaber at the ceiling to cause a collapse and break the stalemate, Axmis destroyed his lightsaber with Ragnos's scepter and escaped with Penin. While Katarn used the Force to temporarily prevent the ceiling from collapsing, Korr used Katarn's lightsaber to cut a hole in the floor, through which they jumped to a lower level. After freeing themselves, they searched the castle for Axmis and Penin, but were unable to find them, leading them to return to Yavin 4.

Upon their return to the Jedi Academy on Yavin 4, Katarn and Korr briefed Skywalker on the events that transpired on Vjun. In recognition of his bravery and skill in defeating the three Dark Jedi, Korr was promoted to the rank of Jedi Knight and granted permission to construct a new lightsaber to replace the one he had lost. Katarn also detected Korr's growing anger toward Penin's betrayal, cautioning him that it could potentially lead him to the dark side.