Kreia, IMO was never really a "bad guy". She was a crazy b*tch, but never a bad guy. Calo Nord, on the hand, was an arrogant SOB I wanted to waste from the first second I saw him. And Malak, well he was just a pathetic attempt at a Darth Vader-like Sith Lord. He was like a kiddie version of Darth Vader, safe and very Bioware.