For the heavy metal band, see; Hellion Hellion (Julian Keller) is a fictional character, a mutant in the , a member of the student body at the Xavier Institute, and a member of the Hellions squad therein. He first appeared in New Mutants (second series) #2.Fictional character biographyNew Mutants vol.2/Academy XBorn to parents who managed to work their way out of poverty to become billionaires, Julian was sent to the Xavier Institute in hopes that he would learn to use his powe