8. The 5th Kryptonite Man (DC Comics)
Several villains have shared the "Kryptonite Man" moniker, but for this point we'll be focusing on the fifth one - K. Russell Abernathy. K. Russell Abernathy was a scientist who, prior to the events that would unfold, was on the verge of something big. Whilst he was working out of a research laboratory on the Avenue of Tomorrow in Metropolis, he developed a Kryptonite isotope enhancer, which would enable Abernathy to harness Kryptonite radiation and convert it into usable energy. Unfortunately for him, the isotope enhancer overloaded, which caused a massive explosion of Kryptonite radiation in his laboratory. Because of the fact that he wasn't protected by lead shielding at the time, Abernathy took the full brunt of the blast. However, instead of killing him, the massive blast of green radiation mutated him into a living Kryptonite Man. As mad scientists tend to do in such a situation, he immediately went on a rampage through the city, causing Superman to intervene (but, obviously, he struggled thanks to the fact that he found the culprit to be made of his weakness). Kryptonite Man fired blasts of Kryptonite radiation from his eyes at the Man of Steel, which enables him to find a place on this list.