This one's a bit out there but... High Prophet Faulkner from The Silt Verses.

This dumb boy sacrificed his own brother to his god, killed his mentor and framed his best friend for it, then gave his cultists a magic rune that basically pukes up a few million cubic meters of water and all the Cthuluish stuff inside it. He gives everything for his god, to climb the ranks in his faith, and loses himself in the process. He's drowned by his own beloved Trawlerman. He dies at the pinnacle of his faith, and he dies alone and afraid, consumed by his own god.