Duel in the Dark Council Chambers (Kaggath)

After Darth Zash commanded her apprentice, Kallig, to eliminate Darth Skotia, Skotia's Master, Darth Thanaton, grew wary of Zash and her actions. Thanaton despised Zash and quickly came to view Zash, along with her apprentices, as pests that needed to be purged from the Sith Empire. Following Zash's supposed demise, Kallig assumed her role and began serving Thanaton. However, Thanaton sought to eradicate all of Zash's followers, and therefore, he attempted to dispose of Kallig. This action would ultimately lead to his downfall. Kallig evaded Thanaton's numerous assassination attempts and successfully established a power base to challenge Thanaton's forces. Realizing that his efforts were futile, even after becoming a Dark Councilor, and after losing multiple apprentices, Thanaton initiated a Kaggath on Corellia with the aim of permanently defeating Kallig. As it became clear that he was on the verge of defeat, Thanaton retreated to Korriban to seek assistance from the Dark Council.

Darth Thanaton made his way to Korriban and proceeded to the Dark Council Chambers to address his fellow Dark Council members. Kallig arrived shortly after, pursuing Thanaton relentlessly. After Kallig overcame Darth Enraj, who had allied himself with Thanaton, Kallig entered the Chamber and confronted their adversary. Thanaton asserted that Kallig and Zash were tainted and needed to be eliminated, but the Council highlighted his personal failure to achieve this. Kallig pointed out that Thanaton had violated the rules of Kaggath, rendering his words meaningless. The Dark Council declared that if Thanaton wished to preserve his reputation and honor, he had to triumph over Kallig in a duel. Thanaton continued to emphasize the importance of tradition, which provoked Darth Ravage, who turned to his fellow Dark Councilor, Darth Mortis, and stated that if neither Kallig nor Mortis intervened, he would personally kill Thanaton. Infuriated, Thanaton proclaimed that he would not be betrayed by the Dark Council, would slay the Sith Lord, and would subsequently hold the Council accountable for their inaction.

Kallig and Thanaton engaged in combat, but Thanaton found himself outmatched and on the losing end. Unwilling to accept defeat, Thanaton unleashed bursts of Force lightning, but Kallig effortlessly repelled his attacks with a mere gesture. The increasingly desperate Sith Lord exerted his full power to kill Kallig, summoning Force storms and projecting Force lightning. Although he managed to briefly restrain Kallig, Kallig, aided by the ghosts bound through the Force walk, endured the assault and dispelled it. Thanaton attempted to conjure another Force storm, but Kallig countered with a potent Force push that slammed Thanaton against the wall. As his opponent watched with folded arms, Thanaton ignited his lightsaber and charged, only to be halted mid-strike and forced to his knees. Thanaton, attempting to conceal his intentions by bowing his head, tried to launch a counterattack, but Kallig anticipated the maneuver and struck him with Force lightning. Severely wounded, Thanaton crawled toward his fellow Dark Councilors. The Dark Council recognized that Thanaton was weaker than Kallig and had therefore lost the Kaggath. Darth Mortis offered an apology to Thanaton before ending his life with the Force.

As Kallig demonstrated superior power, the Dark Council awarded Kallig Thanaton's seat on the Dark Council. Darth Ravage expressed reservations about appointing a mere Sith Lord to the Council, as Darths typically held such positions. Darth Marr silenced him, asserting that Kallig had earned the position. He then addressed Ravage's concerns by bestowing upon Kallig the title of Darth Nox. With this act, Nox became the master of all the Sith and members of the Sphere of Ancient Knowledge, only accountable, along with the rest of the Dark Council, to the Sith Emperor himself. Mortis then concluded the meeting, advising Nox to return to Dromund Kaas to ensure the loyalty of the Sphere of Ancient Knowledge and promising to inform Nox of the next Dark Council gathering.