G.I. Joe: A Real American Hero (1983)

S2E18 My Brother's Keeper

Sergeant Slaughter joins Sci-Fi at a science fiction convention, where they encounter Dr. Mindbender. He lures a disabled scientist into helping him fix his newest weapon, making deceptive claims about restoring the scientist’s ability to walk. As a result, the scientist is manipulated into betraying his own brother for the sake of Mindbender’s ambitions.