Vartox

Vartox is a criminal who was eventually captured and imprisoned in Krypton's high security prison Fort Rozz. When Kara Zor-El escaped the Phantom Zone, she unintentionally dragged Fort Rozz with her which eventually crashed onto earth. This caused the inmates to escape, including Vartox.

He is an antagonist in the 2015 television series Supergirl.

History
Vartox was employed to bring down a plane that was transporting several D.E.O. agents. Although he managed to sabotage the plane's engine, which would have resulted in a crash, the plane was saved by Kara Zor-El, her first act as Supergirl. Vartox is sitting in a diner outside the city where he sees the news reporting about the rescue of the plane and the nameless heroine who saved it. After drinking his coffee, he leaves the diner and climbs into the back of his truck where he makes contact with his employer. The man chides Vartox for the plane's rescue but Vartox defends himself, claiming that while the trap worked perfectly the unknown heroine interfered. The two men deduce that the woman is the daughter of Alura and the employer orders Vartox to eliminate her, regardless of how many innocent civilians die on the way. Vartox assures his employer that both Kara and her city will pay.

He contacts Kara on a frequency with 50.000 hertz. By threatening to make the humans from National City suffer a frequency which would cause them ten times the pain Kara's experiencing, he forces her to meet him at National City Power Plant. Once Kara arrives, he ambushes her, disguised by the surrounding lead. After knocking down Kara, Vartox claims that she looks much like her mother Alura, who was the judge who condemned him to life in Fort Rozz. He states that while he couldn't kill Alura, he is now able to kill Kara as retribution. He grabs Kara and throws her through the area, eventually pinning her down and trying to kill her with his axe. Kara evades the blow, causing Vartox to throw his axe at her. The axe causes a bleeding wound on Kara. Vartox tells her that now she knows how it feels to bleed and that her city will bleed too. He is then scared off by the arrival of D.E.O. agents who pursue him. Varox manages to escape however.

With the unique nuclear thumbprint from Vartox' axe, the D.E.O. manages to track him down. Kara flies to the location, crashes Vartox' truck and engages him in a fight. Eventually, Kara shoots laser beams out of her eye into Vartox' axe, causing it to explode in a nuclear blast. Severely wounded by the explosion, Vartox rams a fragment of the axe into his own body, commiting suicide before Kara can capture or interrogate him. However, before he dies Vartox reveals that not he, but what's coming to National City is what Kara should be worried about.