I want the villain whose true identity is unknown to most, his past as masked as his face, and who evokes fear in his enemies and ally subordinates alike. The main differences between my idea and the character of Darth Vader, are that he can survive without his suit, there's no relation to the hero, nor ever any redeemable factor to him, and I'm not going to give him any magical powers.

Then I still have the hero, the princess, and the rogue. Thinking about combining the hero with the rogue to create something of an anti-hero (cross between Luke and Han... if you can imagine that).