User blog comment:EmpyreanSmoke/Leviathan VS Archangel/@comment-188.4.147.206-20140826134718/@comment-3481504-20140828004406

Oh, no! Humans couldn't hold their head back like Cas did. If a human grabbed a hold of a Leviathan, they could just lash their head to the side sending the human slamming into a wall, maybe even killing them. It has been shown that while celestial beings (except archangels) are weaker than Leviathan, they can combat Leviathan in a way that humans couldn't with their strength. And, if they're immune already, what's the point of negating them?