David Haller is the son of Professor Xavier and Gabrielle Haller. Professor X never learned of David's existence until David was an adult as Gabrielle became pregnant after an affair with the Professor. She never revealed the pregnancy or the birth of their son to the Professor. Haller in the original comic manifested his mutant powers after a traumatic terrorist attack destroying and absorbing the minds of the terrorists in the process. Haller is institutionalized by his half sister.David is considered an Omega class mutant which is the most powerful mutant that exists. Each of his multiple personalities has different powers that manifest themselves during periods of great stress. David is, initially unaware of his abilities.