A twisted wreck, Darth Sion is a Sith Lord held together only by sheer force of will. Every bone in his body has been shattered and rebuilt, turning his skeleton and his flesh into a patchwork mass of bruises and scraping bone. He is in constant pain, and only his hatred and the power of the Dark Side keeps him alive.
Sion is exceedingly difficult to kill – his mastery over his own body (as imperfect as it is), has given him tremendous vitality, and the near-constant agony he endures allows him to ignore attacks and wounds that would cripple or kill a normal human being... or even a Jedi.
Like most of the Sith Lords, Sion has few redeeming qualities. He is a cold, vicious killer driven only by the need to inflict pain and suffering on others – as the leader of a sect of Sith assassins sent to wipe out the Jedi Order, Sion and the player are destined to cross paths.