Beat the game, DLC, all Bosses, all Invaders, mission lines and Hostile NPC's. Sent Greirat to pillage, went right to the Corvians in Archives, killed them, his corpse was still on the ledge. Given the prior close call, his dialogue asking to go the 3rd time and his Umbral Ash discription; It's scripted, he's gone and his corpse is loaded there after any load screen. The game doesn't exactly do happy endings so I'm not shocked but Gray did more to supply us than anyone. Side note, send him to die later in NG to get access to all goodies and get stocked before NG+. Rest in peace, Greirat.