My most feared villainess is the life draining, Succubus. She has a low powered telepathy which she uses in tandem with her ability to take the form of her target's ideal woman (COM:36). She then employs a mid-level Mind Control (1 command: Kiss Succubus {something they wouldn't mind doing with a COM:36}...only vs males) which allows her to use her most devastating attack, her kiss (6d6 Body Drain).
Over the years she's slain 8 PCs leaving nothing but a small pile of powderlike dust.