Supergirl is a character created by Otto Binder. She is Kara Zor-El, Superman's cousin, who was sent to Earth before Krypton exploded. There, she found she had superpowers on Earth due to the radiation from our yellow sun: super-strength, super-speed, invulnerability, flight, micoscopic vision, telescopic vision, x-ray vision , heat vision and freeze breath. She decided to use these powers as Superman's sidekick, Supergirl. Her arch-nemesis is Lex Luthor .