User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-98.231.41.14-20120508204212/@comment-3481504-20120509012126

Totally agreeable. More simply, age doesn't cause power (right from comma, description taken from comment of KevinTheDestroyer) but it can contribute to power.

Leviathans, or at least Joyce, Edgar and Dick, can kill angels, and eat them. Which means Them > Angels. However, I can't see them penetrating an Archangel's vessel, or effectively killing one.

As of yet, after God and Death, Archangels are next as the strongest beings.