Guest Stars Matthew Waterson voices Magneto Gui Agustini voices Roberto Da Costa Chris Britton voices Mr. Sinister Gil Birmingham voices Forge Chris Potter voices Cable Theo James voices Bastion Ron Rubin voices President Kelly Theo James voices Sentinels Credit Only Catherine Disher voices Val Cooper JP Karliak voices Hulk Uncredited JP Karliak voices Hulk (Morph) JP Karliak voices Mr. Sinister (Morph)