Conquest of the Invincible series would be easy to beat.

The man has one eye. Stop punching him in the face and start poking. Once his eye is popped he is blind. Yes, he still has ears however a dozen sonic devices can limit his ability to use his hearing or better yet fight him in space. no sight or hearing it is like fighting Helen Keller. Hit and run tactics until he is dead. He will get worn down eventually and succumb to the attacks or eat starve/dehydrate to death. The mighty conquest would be easy to conquer.