Source: comicvine.gamespot.com

9. Evil Star

On the planet Aoran, one man wanted to conquer death itself. He was convinced that this was possible only through harnessing the powers of the stars themselves.

He created the starbrand, a device that did indeed grant him immortality. However, the device also compelled him to commit "only evil acts", which sounds like an excuse. That sounds like someone not taking responsibility for their own actions, Evil Star.

God, the old "blaming your faults on the constantly pulsing mechanical band of star-harnessing technology on my wrist" excuse, SUCH a cliché.

Anyway, Evil Star eventually stepped too far off-planet, and got slapped down by Hal Jordan. The Guardians forced him into rehab (this is not a joke; this is a real thing), but he eventually broke out and returned to fight for evil once again.