Do you want to compare Ultron with John Constantine? Discover the powers, weakness & weapons of Ultron and John Constantine from Ultron Biography and John Constantine Biography. Find out all about Ultron and John Constantine.# Check out how is Ultron unique and distinct from John Constantine. Discover their love interest, sidekicks, family tree and the movies and games list in which Ultron and John Constantine have appeared. Find out everything about them here!