|First appearance||Daring New Adventures of Supergirl #8 (June 1983)|
|Created by||Paul Kupperberg (writer)
Carmine Infantino (artist)
|Alter ego||(Pre-Crisis) Ben Krullen
(Post-Crisis) Benjamin Martin Krull
|Team affiliations||(Krull) Suicide Squad
|Abilities||Generates lethal radiation|
Reactron is a fictional supervillain in the DC Comics Universe, who has appeared in at least two versions. He originally appeared in The Daring New Adventures of Supergirl #8 (June 1983), in a story written by Paul Kupperberg and drawn by Carmine Infantino.
Fictional character biography
Ben Krullen was a sergeant serving in the US Army during the Vietnam War, alongside future Doom Patrol member Joshua Clay (Tempest). When Krullen massacred the inhabitants of a Vietnamese village, the shock triggered the activation of Clay's mutant powers. Clay seemingly destroyed Krullen with his energy blasts, then went AWOL.
Krullen, instead of being killed, is transformed into a being capable of generating radioactive energy and concussive blasts. Calling himself Reactron, the Living Reactor, he surfaces years later and attacks the Doom Patrol, then later fights Supergirl.
Reactron's origin and background were changed for his appearances after the Crisis on Infinite Earths limited series. Now known as Benjamin Martin Krull, he faces the Doom Patrol and Power Girl in his first appearance. Most of his pre-Crisis continuity seems intact, but it is now said that his previous battles involved Power Girl instead of Supergirl.
Seemingly destroyed after overloading on Negative Woman's energy, he resurfaces unharmed and as a member of the Suicide Squad. Reactron is once again seemingly destroyed when Deadshot shoots holes in his containment suit, causing him to go critical.
He, Mister Nitro, Geiger, Nuclear, Professor Radium, and Neutron formed the Nuclear Legion in the pages of Battle for Bludhaven, working for The Society, and came into conflict with Freedom's Ring, which kills Reactron. 
Reactron appears during the "Superman: New Krypton" storyline with a new costume and a new ability. Recruited by General Sam Lane as part of his Project 7734, Reactron is equipped with a heart made of gold kryptonite and partnered with Metallo (who has a heart of green kryptonite). Reactron and Metallo attack the city of New Krypton, where Reactron kills Zor-El, the father of Supergirl. As part of his participation in Project 7734, Lex Luthor sends a robot double of himself with Brainiac on a mission to attack New Krypton, a new planet in Earth's solar system populated by the survivors of the Kryptonian city of Kandor. While there, the Luthor robot tampers with the body chemistry of the previously-captured Reactron. Shortly thereafter, Reactron kills himself, initiating a chain reaction which ultimately destroys New Krypton and all but a handful of its 100,000 inhabitants. Supergirl's mother Alura (who had assumed leadership of the planet) is among the casualties.
Powers and ability
In both Pre-and Post-Crisis continuities, Reactron has the ability to generate radiation from his body. He can focus this into concusive blasts. Currently, Reactron is also equipped with a heart made of a gold Kryptonite variant, which allows him to render a Kryptonian powerless for 15 seconds.
- Daring New Adventures of Supergirl #8 (June 1983)
- Daring New Adventures of Supergirl #9 (July 1983)
- Doom Patrol vol. 2 #10 (July 1988)
- Secret Origins Annual #1 (1987) and Who's Who Update '87 #5 (December 1987)
- Suicide Squad vol. 2 #6 (April 2002)
- Suicide Squad #8 (June 2002)
- Supergirl vol. 5 #52 (June 2010)
- Superman: War of the Supermen #1 (July 2010)
- Superman/Batman #77
- Action Comics #872 (February 2009)