Supergirl, Vol. 5 #38A

Origins & Omens - Who Is Superwoman?, Part Two: Clashes
Supergirl, and the mysterious new Superwoman struggle high above the Earth. Superwoman is desperate to keep Kara from returning to Earth, despite her Mother's orders to find Reactron, the murderer of Zor-El, to face Kryptonian justice. And what's more, Kara wants to make Reactron pay for her father's death. And she thinks she knows who this new Superwoman is. But Superwoman is answerable to powers here on Earth, and they want Reactron for their own.
Release Date: 2009