Creation
The Atom Man was originally introduced in the Superman radio serial as a Neo-Nazi villain that Superman would routinely fight. He was created by the Nazi scientist Der Teufel as a genetically enhanced human powered by liquid Kryptonite. He was given the name Heinrich Milch by Teufel, but while in the US he would go by the alias Henry Miller to conceal his German origins. The Atom Man would then be featured in the film Atom Man Vs. Superman, but this version of Atom Man took on the alias of Lex Luthor. Outside of using the alias Lex Luthor, the character remained the same in the film. It wasn’t until the 2019 graphic novel Superman Smashes the Klan that Atom Man was introduced into the comics.
Superman Smashes the Klan
The Atom Man was an unknown supervillain who was subjected to Nazi experiments using Kryptonite. Using his newfound power, Atom Man invaded America seeking revenge on American citizens. Atom Man attempted to bring down the Metropolis Dam. But he was stopped by Superman and taken into custody.
Earth-Two
Heinrich Melch was a soldier in Nazi Germany whose father was charged with developing a plan to stop Earth 2 Superman (Kal-L). Heinrich used a kryptonite chemical his father invented to became a super soldier. Heinrich’s first attempt failed and he was presumed dead. Many years later, he was transported to Earth-One, where he gained additional powers.
He attempted to kill the Earth 1 Superman but was foiled by Earth-One’s Superman and Batman. He was transported back to Earth 2 and captured by Earth 2 Superman and Robin.
In Other Media
Superman and Lois
Henry Miller/Atom-Man, is an arsonist and Neo-Nazi who fought Superman during his early years.