Source: dc.wikia.com

7. Kryptonite Man

Multiple men have taken up the title of The Kryptonite Man, so let’s talk about them.

The first was an unnamed alien boy who had an unnamed alien dog. Both passed through a cloud of Kryptonite dust, gaining Kryptonite powers. The boy dubbed himself The Kryptonite Kid, and started messing with Superman. When he grew up, he adopted the Kryptonite Man identity.

Later, Scientist K. Russell Abernathy had an experiment go horribly wrong, and he was blasted with untold amounts of Kryptonite radiation. After Supergirl threw him in jail, Lex Luthor broke him out. He did this by…um…by using a group of semi-sentient fleas called The Flea Circus? I…I don’t believe that. That sounds insane. This is in a comic from, like, 2008. That sounds like some 50s stuff. Luthor strapped K-Man to a big machine, and ripped his powers out of him.

And that was the last we saw of The Kryptonite Man.