The origin of Super Villains: Kryptonite Man

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https://en.wikipedia.org/wiki/Kryptonite_Man

The first character to use the name was Lex Luthor, who appeared as the Kryptonite man in Action Comics #249 [1]. The second character to use the name first appeared as the Kryptonite Kid in Superboy #83,[2] and as Kryptonite Man in Superman #299.[3] and was created by Jerry Siegel and George Papp.

The K. Russell Abernathy version of Kryptonite Man first appeared in Superman #650 and was created by Kurt Busiek, Geoff Johns, and Pete Woods.

The Clay Ramsay version of Kryptonite Man first appeared in Action Comics Annual #1 and was created by Grant Morrison, Rags Morales, Sholly Fisch, and Cully Hamner.

Pre-Crisis
Lex Luthor
Lex Luthor drank a serum dissolved from a Kryptonite meteor he found to gain the ability to emit Kryptonite radiation.[4]

Kryptonite Kid
The original Kryptonite Man started out as a teen-age alien criminal called the Kryptonite Kid.[5] On the planet Blor. Facing a 20 year sentence, he volunteered for a scientific experiment, a satellite that required a test passenger. He favored dying in deep space to rotting in jail, with the added bonus of a 10,000 to 1 chance of surviving the test.

He was loaded in the satellite together with a laboratory dog, and the satellite was shot into deep space, never to return. To pass the time, they watched a telescopic viewer of Earth and learned of Superboy's existence. On their course for Earth, they passed through a green cloud of gaseous Kryptonite. Exposure to the Kryptonite turned both him and his dog green, bestowing each of them with Kryptonite-based powers. This incarnation is most well known pre-Crisis on Infinite Earths from his appearance and death in the non-continuity story Superman: Whatever Happened to the Man of Tomorrow?. In this story, he is depicted as somewhat older and uses the name Kryptonite Man. [6]

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