They have attacked the mansion to steal the power circuit. Cyclops, Havoc, and Vulcan are brothers Professor X and Juggernaut are Step Brothers Nightcrawler is the son of Mystique and Azazel Rouge is the foster Daughter of … Home. AskLogin. He does nothave a natural brother. Cain Marko, the Juggernaut, is his step-brother. AskLogin. He had an older stepbrother named Cain Marko… He is also a member of the Brotherhood of Evil Terrorists. In Uncanny X-Men #12, Professor Xavier fills the X-Men in on the Juggernaut's origin. Wolverine (X-Men) Cyclops … Who is professor X's brother - Answers. Charles Xavier was a smart and sensitive young boy. Juggernaut is Professor X's half-brother. The character previously appeared in X-Men: The Last Stand, but there was nothing there to indicate Cain Marko had a familial relationship with the mutant leader Professor Xavier.