User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-210.2.185.244-20120516005943/@comment-98.113.182.208-20120516012139

no they are not immune to archangels. Nor can they kill them. want proof?

God Cas with 30 million souls have kept an ENTIRE 'species' of leviathans at bay for over a week. God Cas is﻿ equal to Michael and Lucifer. Cas's quote is: "We need to keep Michael in Lucifer's cage." It took an entire group of leviathans to eventually poison God Cas and take over his vessel.

One Leviathan doesn't have no where near enough black goo juice to poison and kill an Archangel. And I'm confident the archangels will over-ride the leviathan's immunity.