I'm not really into insane characters, but it can be interesting, sometimes even challenging to fit them in storyline without being categorized as a person that is impossible to play with. Many think insane means unable to RP with, but it doesn't. It depends on the player through. If the character is unable to RP normally with it means it's powerplaying by many dodges, never being hurt, killing everyone he can the players will roll their eyes and probably head to block button. The worst thing then isn't the player's fight for pixel life if the player is being annoying by going to every single person and trying to kill. But if character kills/attacks for reason, with realistic movements and actual plan it makes the RP interesting. I hope you understand what I want to say- insane characters aren't bad if the floof behind the screen knows how to use them to mess up with storyline, still managing to produce some kind of fun to others since it's much interesting to deal with killer than describe how you sit on rock.