I will join that club. All the characters from my Alien Fiction series are eithe dangerously insane, evil, or both. I am talking about dozens of characters, and they are all undateable. The closest to a sympathetic character I have is Doctor C'thulhu, an uplifted octopus working as an archeologist, and that just isn't my kink (because he is a dude). Candide or Morgan le Faye might be fun for a hook up, but don't stay the night if you value your life.