Those of clan Malkavian are all insane, but the character affectionately known as Tourette has it bad- two polar opposite "sisters" who share a body and dislike one another to the point where one tries to shoot the other (you see how that would be ill-advised).
Literally the god of madness, he contradicts himself and basic rules of logic at all times. Presiding over a psychedelic dimension filled with madmen, he is about as far from sane as possible.