User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-3045936-20120118013836/@comment-3045936-20120118031502

Agreed. I doubt the Leviathans are even directly stronger than angels one on one anyway. But as of yet there is no permanent way to kill them. Minus of course if you God, Death etc. Also I just thought of something. Remember how Castiel said This is a vessel. My true form is approximately the size of your Chrysler Building. I wonder how a battle between spiritual beings are. I mean Angels and demons true form are ethereal or spiritual. Even certain deities while appear on Earth as human have true forms with stating by Atropos as she can go to Heaven a ethereal plane of existence. Who knows maybe rules, laws, etc in the physical realm aren't the same even for supernatural things as it is in the ethereal ones like Heaven, Hell, Purgatory etc.