Albedo (Ben 10: Alien Force)

Azmuth's former assistant, and Ben's new Evil Counterpart after Kevin's Heel–Face Turn. Originally a Galvan, Albedo asked his master for his own Omnitrix. When Azmuth refused, he created a copy of it and set it to match Ben's. However, since Ben's Omnitrix had Ben's DNA as the default form, it ended up turning Albedo into a clone of Ben with the same alien transformations, but unable to turn back to his original form. Since then, Albedo is obsessed with getting his hands on the Omnitrix so he can use it to turn back to normal.