User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-101.160.191.17-20120522085708/@comment-3481504-20120525032559

Actually, that could makes sense, John432. Well, just imagine how big they'd have to be to eat an Angel, who's form is comprised of a portion as big as skyscrapers.

Also, it ("You know, Leviathan can kill angels. There's a reason why Father locked them in Purgatory. They're the Piranha that would eat the whole aquarium.") implies that everything living (except for God and Death) can be eatable by a Leviathan, except, although living, Archangels couldn't be.