Desann – Jedi Knight II: Jedi Outcast
Unlike most of the characters on this list, Desann isn’t actually a member of the Sith. Instead, he’s a Jedi that has gone Dark by way of a pretty tragic backstory.
We learn in Star Wars Jedi Knight II: Jedi Outcast that this Chistori was not only shunned by his own people because of his strange abilities, which turned out to be the Force, but that even his fellow apprentices felt he didn’t belong. They pick on him pretty ruthlessly, telling him that he is far too weak to ever actually become a true Jedi.
This bullying and hatred eventually pushes Desann toward the Dark Side, taking a once-promising Jedi and turning him evil. This tragic backstory makes him one of the more sympathetic characters to fall to the Dark Side, as you can really understand why he went down this path.
Aside from just being sympathetic, he’s also pretty powerful, favoring the combat form of Dun Moch because of his large stature and power. His abilities include use Force Grip, the Jedi Mind trick, Force Illusion, and Force lightning just to name a few.