Yes, technically Prince got Stanley damned. Point well taken. Still, I can't help but love this guy.
Prince, ruler of the Planet Fire (Hell, essentially) isn't a member of the ongoing cast, he's more of a guest character. Portrayed by Nigel Bennett (who's also quite a catch), Prince'd have to be my favorite guest of the series.
Why? Well - the first thing would be his costume. That coat simply rocks! Having missed the fact that City TV (A Canadian channel) airs current episodes (of Season 3), I only first saw him in 3.12 - The Beach. One of the first impressions that episode gives us is of him kneeling down to look onto Stanley, who's just been washed ashore. The image was just so haunting that it's stuck with me ever since.
Secondly - Prince isn't entirely "evil" in the classical sense. He never chose to be evil, he just has to be by matter of natural course. He's been around since the creation of the Universe, eternity after eternity, and though he first may appear as a type of serpent-with-the-apple, we soon find out (in 3.13 - Heaven And Hell, anyway) that he's also grown weary of his existence ("The planet is about to be destroyed," Kai tells him as they are sitting in a rocky desert - "I know," Prince answers, "I think I should be sad." - with a voice of indifference, even as the nova blast engulfs the area, later he appears to Xev, saying - "Thank you...for releasing me.").
Maybe, essentially - Prince isn't evil at all. What humans hate to recognize is that there's a balance. Dark and light. There has to be darkness - so there has to be Prince. Though he's constantly trying to destroy the Water planet, he admits himself that he'll never succeed, and he knows this. As Xev destroys the Fire planet, it is Prince's doing that the Water planet also goes, to re-establish balance. It's very likely that had Water been destroyed first, Fire would've followed.
Prince is goth with maybe just a dash of a bad guy thrown in for good measure - which is what makes him so neat.