User blog comment:Collbrande-Ex-Caliburn/Hyoudou Issei's Peerage composition hopes/dreams/hypothesis/@comment-26821288-20161228004608/@comment-31137559-20170128042330

The last time I checked, Thanatos was the god of death. He is basically the embodiment of death. Hades is the god of the underworld. Thanatos is like Hades' lieutenant and right-hand man. And in DxD, he would be the commander-in-chief of the Grim Reapers I guess.