Diamalon was a member of the Green-Lantern Corps assigned to Sector 1416. He is assigned partnership with long-time veteran Chaselon. During the Sinestro Corps War, he was fatally shot through the head by Sinestro Corps sniper Bedovian. Chaselon swore to Diamalon's parents that he would ruthlessly hunt down their son's killer. Diamalon is memorialized in the Crypts of the Green-Lantern Corps. During The Blackest Night, he is resurrected as a member of the new Black-Lantern Corps.