After exposure to a potion during a battle with the alchemist Diablo, Johnny finds his powers greatly increased -- and his personality turning evil.

Doctor Doom creates a super Doombot to face the Fantastic Four. The Four try and retrain this robot to be one of the good guys. In the end, Ben becomes the super Doombots friend and names him "Bruiser" , but then Doom's control is too strong and the super Doombot captures Susan and Reed. Johnny and Ben must save Susan and Reed, and fight Doom. But when Johnny is captured, Ben is left to fight Bruiser.