Darth Malak

Darth Malak is the main antagonist of the first Knights of the Old Republic game. He was once an apprentice of Darth Revan, the leader of the Sith. However, things changed. When the Jedi Knights, including Bastila, confronts them, he betrays Revan, having taken over the Sith and being responsible for his amnesia. Since then, he orders the planet Taris to be destroyed, and the other planets. Later, he captured Bastila and tortures her until she joins the Sith. Revan manages to confront him and kill him.