Source: whatculture.com

3. Metallo

John Corben was either a professional con man or a decorated soldier (depending on which version of continuity we're talking about). Either way, he wound up being rebuilt into a kryptonite-powered weapon.

John was built as a robot with a Kryptonite power source for a heart. And so, whenever Superman showed up, he could just open his little chest compartment and blast Supes with some K-rays. That was pretty much his one trick most of the time. Until, that was, the Demon Lord Neron called Metallo to come make a deal. Neron said he would boost Metallo's powers"¦ at the expense of his soul. OOooOOOOOOoooooOOO!!!!

Metallo took the deal, and gained the ability to move his consciousness into various pieces of machinery. Like Ferris wheels or battleships.

During this time, he fought the newly Electric-Powered Superman. It was a real odd time for both of them.