What if we dig deeper into the meaning of monster, and Monster Boy can turn into metaphorical monsters? Like serial killers or something. OK, maybe a bit too creepy.
Re 1000 year old movies... is it 1000 years old relative to when Monster Boy is? Like if he goes to the past, he can... uh... turn into a T-Rex or something? But if he goes back to the 31st century, he can... I don't know... turn into King Kong?
Keep it going guys. You are brightening up my day.
Happy to help a bit, stile