Aggressive Atomic Anomalies Antagonize Avengers

Nathaniel "Nat" Tryon  was one-third of the T.N.T. Trio, henchmen of Lex Luthor tasked by him to damage a nuclear reactor for some undisclosed reason. When the Superman of Earth-One confronted and captured Nat's two associates Ted Grand and Tim Moore, the pair stated they were operating alone. Left pinned by lead shielding, some time after Nat freed himself and approached Lex at one of his Luthor Lair locations. The criminal mastermind stated that Tryon had been afflicted with radiation poisoning, when Luthor promised to cure using a special ray. As Lex was captured a few days later, this left Tryon underneath the ray for an entire year, transforming him into the atomic powerhouse known as Neutron. Battling Superman solo, then as a pawn of Vandal Savage and the Fearsome Five, he met defeat.

Brett Bryson was employed at Chalmers Laboratory, when an accident gave him superhuman abilities that made him a match for the Superman of Earth-Two, with a side effect of being terminally ill. Frank Chalmers convinced his former employee to begin a crime spree with his ill gotten gains going to support his soon to be widow, As the Ghost, Bryson had several confrontations with the Man of Steel, until he learned that it was Chalmers who had manipulated the accident to make him his pawn, at which point he took the businessman's life while his own was also extinguished.

Sergeant Benjamin Krullen serving in the military in Vietnam and cracked under pressure. Exposed to dangerous levels of radioactivity, Krullen from atomic testing, it was left to the crime syndicate Council that provided him a suit harnessing his abilities. Krullen's Reactron alter ego initially drew the attention of the second incarnation of the Doom Patrol, which were particularly interested in the villain as member Tempest had served alongside Krullen in the military and knew how dangerous he was. Supergirl figured creating a superspeed vortex thrusting Reactron into space would cause him to vaporize.

Railroad president Russell Keen sought to take control of all transport in North America, and use his electricity-dampening devices to achieve this goal. Yet despite his technology, and having captured Wonder Woman who opposed him, he was overwhelmed by the Amazing Amazon who deceively defeated him and exposed him to the world as the criminal mastermind.