Marvel Comics character David Haller, also known as Legion, the powerful, schizophrenic mutant son of Professor Charles Xavier. His condition is a manifestation of his omega-level mutant abilities, which include a vast array of psychic powers, and he struggles with hundreds of distinct personalities, each possessing different powers, all fighting for control. He is both a powerful ally and an adversary to the X-Men, depending on whether he can control his mind and powers. Legion looks like a man with long black hair and mismatched eyes – one green and one blue. He has a standard human appearance, though his complex mental state often influences how he presents himself through his numerous alternate personalities and superpowers, which are linked to his dissociative identity disorder.