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"I want the Man of Steel to suffer. I want him to know what it feels like to lose everything. Starting with you."
—Ben Krull to Kara Danvers[src]

Ben Krull is a former reactor engineer of Bakerline Nuclear Power Station. After surviving high radiation exposure which killed his wife, Alyssa Krull, he became a supervillain dubbed Reactron by the Daily Planet (specifically, James Olsen)[1] and began a vendetta against Superman. Krull later targeted the Man of Steel's cousin, Supergirl, but was eventually defeated.


Early life[]

Ben Krull worked as a reactor engineer at the Bakerline Nuclear Power Station. At some point, he fell in love with and married fellow engineer Alyssa.[1]

Becoming Reactron[]

In 2010, terrorists attempted to start a meltdown at the power station, causing intense radiation to flood the building. Alyssa was killed from the exposure and Ben was also presumed dead. However, Ben managed to survive, albeit left with severe radiation sickness.

Heartbroken and vengeful, Ben grew to blame his wife's death on Superman, who didn't have enough time to save them. Fashioning an advanced biomedical technology suit, Ben became a frequent foe of Superman, with neither coming out on top. Despite their stalemates over the years, Ben came close to killing Superman during one of their countless encounters.[1]

Seeking out Supergirl[]

In late 2015 in National City, Ben was working in his scrapyard when he saw the news confirming Supergirl's relation to Superman. Wanting Superman to know what it was like to suffer and lose everything, Ben planned to kill the superheroine. He caused a multiple car collision on the highway to bait Supergirl. Once she arrived, Ben proceeded to attack her with his energy blasts. The two battled until Supergirl hurled a car door at Ben, damaging his suit. Ben then flew away from the scene.

Ben then broke into Lord Technologies, demanding someone with a background in nuclear fission to fix his suit. He initially decided to kidnap an engineer, Carl, until CEO Maxwell Lord intervened, claiming to be better suited to the task, so Ben took him instead. Back at his scrapyard, Ben held Maxwell hostage and demanded he repair the suit, or die. Maxwell deduced the suit's moderator was damaged and listed the required compounds needed to fix it. Recognizing Ben's condition, Maxwell offered to have his team at Lord Technologies help him, but Ben claimed his "normal life" didn't work out as he mournfully gazed at a picture of himself and Alyssa.

After Maxwell fixed the Reactron suit, Supergirl tracked him down. Ben ambushed Supergirl and the two fought. Supergirl tried to appeal to Ben, stating Alyssa wouldn't want him to do this, but Ben declared he was "already dead". Ben incapacitated Supergirl with his nuclear blasts and beat her into submission. As he was about to kill her, Superman arrived and shielded his cousin, forcing Ben to flee.

That night, Ben crashed a gala for CatCo Magazine, looking for Supergirl. He first targeted Maxwell, but Supergirl intervened. When a stray blast damaged a pillar, Ben began to attack Supergirl as she held it up but was lured away outside by James Olsen, who revealed himself as Superman's best friend. While flying after James, firing nuclear energy blasts at him, Ben was tackled out of the sky by Supergirl. After a brief battle, Supergirl ripped out the plutonium core of his suit and encased it in lead, neutralizing Ben's powers and rendering him unconscious.[1] Afterwards, Ben was presumably arrested by the police.

Powers and abilities[]


  • Powers via Reactron suit: All of Ben's powers come from his suit, powered by Thorium 232.
    • Nuclear energy blasts: Ben's suit can fire incredibly powerful blasts of concentrated nuclear energy. These blasts were capable of wounding and even killing a Kryptonian after multiple hits.
    • Enhanced strength: Ben's exo-suit enhances his strength, allowing him to contend with Supergirl and Superman in unarmed combat.
    • Flight: Ben's suit gives him the ability to fly, presumably as fast as Kryptonians. It shown when Superman showed up he flew up into the air and escape quickly.


  • Genius-level intellect/Master engineer: Ben was a successful reactor engineer before his accident. As Reactron, he built an advanced nuclear-powered exosuit to sustain his life after being exposed to a lethal amount of radiation.
  • Expert hand-to-hand combatant: Ben fought Superman multiple times for many years, with neither one coming out a winner. During one of his battles, he almost managed to kill Superman. In one of his fights with Supergirl, Ben was able to send energy into the arms and legs of his suit to enhance his punches and kicks, fighting toe-to-toe with the superheroine.[1]
  • Indomitable will: Despite suffering from intense radiation sickness, Ben never gave up his years-long desire to avenge Alyssa's death by killing Superman or those closest to him.


  • Radiation poisoning: Ben was exposed to intense radiation at Bakerline Nuclear Power Station from its overloading core, which almost killed him. Although he survived, Ben suffered from respiratory distress, skin desquamation, and ulcering.[1]
  • Power core removal: Removing the power core from Ben's suit will cause it to shut down, preventing Ben from using his powers.


  • Reactron suit: Ben wore an advanced armored suit during his exploits as the villain Reactron.



Season 1[]

Behind the scenes[]

  • In the DC comics, Reactron first appeared as first a member of the Nuclear Legion, and later a recurring villain of Supergirl, serving as her archenemy before the New 52 revamp.