Evil Characters - don't care whats right right is for the morally good people, they want to be bad.
I read in some D&D book once the definition of the evil alignments. Which gives a bit more insight in evil itself according to D&D. They explained it like this:
Chaotic Evil: I want it NOW i.e.no patience, no plotting, no care for what's right or wrong, no empathy, no code, evil just to be evil;
Neutral Evil: I want it i.e. basically just opportunistic, a little more care into it than chaotic but if it's there and there's no risk then why not;
Lawful Evil: I want it ALL i.e. ultimate power over everything, a planner, still adhering to some personal code (e.g.no lying).
So I'd say a certain type of greed is still at the heart of things evil. Not being evil for the sake of evil depending on which side of the spectrum you are.
