InsaneJournal

It's Evil Star.



"Who?", you ask. Well, let Wikipedia educate ya.

"A scientist on the planet Auron dedicated himself to cheating death by drawing power from the stars themselves. He invented the starband, which made him immortal, but twisted his mind toward evil and prematurely aged his fellow Aorans. The people of Auron wanted him to destroy the starband, but having tasted immortality he refused to give it up. The ensuing battle left all of Auron lifeless except for the scientist, now known as Evil Star. Evil Star sought new worlds to conquer and came into frequent conflict with the Guardians of the Universe and the Green Lanterns, including Hal Jordan."

"Evil Star's primary weapon is the Starband. The Starband draws the energy of the stars to prolong Evil Star's lifespan, create force blasts or hard light constructs, and powers the Starlings. Starlings are miniature versions of Evil Star that possess superhuman strength and invulnerability, and are under his complete control. Starlings need direct commands from Evil Star to function, and they become directionless if he is unconscious. If Evil Star is kept away from starlight for a prolonged period, his powers fade away."

There's also what seems to be a throwaway line about Evil Star conquering Sister Sercy's planet here. With the entirety of the War of Light, the Blackest Night, and the future appearances of Krona, Cyborg Superman and, evidently, Evil Star, Geoff's got a lot on his plate.