An aged Human male, Darth Xedrix held the distinction of being a Dark Lord of the Sith. He was a member of the Dark Council within the reconstituted Sith Empire, and the longest-tenured member of the Council. By 3954 BBY, he joined forces with Darth Nyriss and five other Council members to overthrow the Emperor, whom they deemed arrogant, excessively powerful, insane, and whose plan to assault the Republic was considered suicidal.
To conceal their conspiracy from the Emperor, Darth Nyriss orchestrated fake attempts on her own life. Initially, Nyriss intended for her own followers to investigate these incidents, but the Emperor dispatched Lord Scourge, leading to a change in plans. Sechel, one of Nyriss's subordinates, along with Scourge, discovered that a group of Human separatists originating from Bosthirda were responsible for the assassination attempts. During a raid on the separatists' compound, they uncovered evidence linking Xedrix to the group.
Scourge, utilizing a replica of the separatists' coded communications, sent a message to Xedrix, posing as the separatists and requesting a meeting at a cave located on Bosthirda. Xedrix journeyed to the designated location, accompanied by a male Human apprentice and a female Human apprentice. Upon their arrival, Scourge ambushed them, swiftly defeating and killing both apprentices. Xedrix, weakened by age and his reliance on the dark side, watched the entire scene unfold without intervening. He then mustered his strength for a final attack, unleashing a potent and devastating blast of Force lightning at Scourge. Despite being surprised and injured by the elderly Sith Lord's attack, Scourge quickly recovered and prepared to eliminate Xedrix. Xedrix attempted to sway Scourge to his cause, falsely claiming that Nyriss had sent him to die and, truthfully, revealing that she was manipulating him as a pawn in a larger scheme. Unconvinced, Scourge, realizing the Sith Lord was as weak as Nyriss had described, killed Xedrix and presented his severed head to Nyriss as proof of his demise.
Darth Xedrix possessed a remarkable ability to conceal his true emotions behind a veil of dark side energy. In his battle against Scourge, Xedrix masked his fear of death at Scourge's hands behind a "swirling maelstrom of dark side energy," which enabled him to gather the Force for a final offensive.
Xedrix also demonstrated the capacity to generate purple Force lightning potent enough to incinerate his adversaries.