Fan Casting Riddler in Ben 10/Justice League: The Series

The Riddler is a super-villain enemy of Batman who commits crimes revolving around an obsession with riddles. His mental psychosis results from a deep inner need to prove that he's smarter and therefore better than others, which causes him to leave challenging clues behind in otherwise perfect crimes. This psychological compulsion has resulted in him being repeatedly imprisoned in Arkham Asylum. Despite this obvious flaw, he is otherwise an extremely intelligent criminal mastermind.