>>105067031Metallo as he is mostly known is really mostly a Post-Crisis creation. He was just a criminal in power armor in the Golden Age.
Then the Silver Age version was the cyborg with the Kryptonite heart, but that version died in his debut story and he didn't really have a "villain look". He just looked like a normal man in a suit and then opened his chest when necessary in his one appearance.
There was also a story where Clark was split into two and the powerless one turned himself into another Metallo before they merged together again. Yet again though, he just looked like normal Clark, with the heart only opening at a certain point.
The third Metallo created near the 80s had a super villain costume look with a green skull and a mark on his chest, but it wasn't actually open most of the time.
Then post-crisis, they rebooted the silver Age Metallo and gave him his mostly known robot look with a constantly open heart and the various one shot powers.
