In the Supergirl episode “Fight or Flight”, Ben Krull aka Reactron arrives in National City, and he’s seeking revenge. He has it in his mind that the best way to finally beat his arch enemy Superman is to kill his cousin Supergirl. Armed with a suit powered by nuclear energy, Reactron will definitely test the powers of Supergirl (Melissa Benoist).
Ben Krull/Reactron is portrayed by Chris Browning. He’s appeared on several TV shows including Bones, Ray Donovan and Major Crimes but he’s best known for his recurring roles on Agent Carter (Rufus) and Sons of Anarchy (Gogo). Browning is also recognized for his roles in the films 3:10 To Yuma
