Darth Mortis looking upon Darth Thanaton after telekinetically snapping his neck.
After the Wrath killed Baras, Darth Vowrawn led Mortis and the others in acknowledging the truth of the Emperor's support for the warrior, accepting that the Wrath was not bound by the Council's wishes. When the Wrath departed, Darth Thanaton brought his own matter before his fellow Councilors: the head of the Sphere of Ancient Knowledge was engaged in a Kaggath, an ancient Sith ritual duel, against his rival and subordinate Lord Kallig. After being bested by Kallig on Corellia, Thanaton appealed to Mortis, Ravage, Vowrawn, and Marr to eliminate the upstart slave, though the other Dark Councilors refused to interfere when Kallig arrived to continue their battle. After Kallig defeated Thanaton and forced him to submit, Mortis rose from his seat and apologized to his fellow Councilor before breaking his neck with the Force. Acknowledging Kallig as the victor, the four Dark Councilors present rewarded the young Sith Lord with Thanaton's now-vacant seat on the Council, and they brushed off the newly-appointed Darth Nox's question when the Emperor would meet with the Council. As the Council adjourned, Mortis advised Nox to return Dromund Kaas and ensure the loyalty of their followers, promising to summon Nox the next time the Dark Council congregates.[4]
Darths Vowrawn, Marr, Mortis, and Ravage were among the few surviving Council members after Corellia.
After the Battle of Corellia ended with a Republic victory and the deaths of Decimus, Hadra, and Acharon, the Dark Council was angered to learn that the Sith Lord Darth Malgus declared his own empire on the planetIlum—an empire that did not discriminate against alienspecies and was not beholden to the political infighting that the current Empire was. Mortis assumed a leadership role on the Council along with Marr and Ravage, dispatching Grand MoffIlyan Regus and Darth Arho, Baras' successor as head of the Sphere of Military Offense, to conduct the campaign against both Malgus and the Republic there.[6] Mortis and the other Councilors would later meet in their chambers beneath the Imperial Citadel on the capital of Dromund Kaas to debate who would succeed Darth Hadra as the head of the Sphere of Technology, and Mortis was one of several Councilors who refused to support Darth Marr's candidate, the FalleenDarth Karrid. Mortis believed that the Empire was wrong in adopting Malgus' policy of allowing aliens to join their ranks, and he proposed the Human traditionalist Darth Gravus in opposition to Karrid. To that end, he tried to convince the rest of the Council to grant Gravus a seat once he reclaimed the mineral-rich world of Leritor.[5] After Karrid disposed of Gravus, Mortis chose to support Karrid, admitting that he had underestimated her.
During Makeb invasion by the Hutt Cartel, Darth Mortis summoned an Imperial individual to assist him against The Shroud, a spy who wanted to plan a rogue attack on Dromund Kaas. The Dark councilor introduced Evie Bo, the ex top-lieutenant of The Shroud, to the Imperial individual who gave him the microbinoculars in order to find another lieutenant in the city and stop The Shroud.
"Elevating a Falleen to the Council shows other species that there is a place for them in our Empire." "Perhaps the problem is that the other species have forgotten their proper place."
A Human male with redeyes, pale skin, and black hair, Mortis was among the older members of the Council by the end of the Cold War.[1] He did not place much faith in Sith traditions, though he was a believer in the Empire's anti-alien policies and—something that led him to support Darth Gravus over Darth Karrid when the Dark Council was considering whom to give Darth Hadra's Dark Council seat to.[5] Nevertheless, he changed his tune when Karrid outmanuevered and defeated Gravus, realizing that he had underestimated her.