User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-108.67.188.26-20140602152156/@comment-173.56.242.102-20140626212834

Again. No. If it were that simple, then Sam and Dean wouldn't be able to kill a Leviathan, which they have numerous times. As well as the fact that an archangel, or even an angel, could simply behead a leviathan to kill it.