User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-184.77.255.73-20111214195052/@comment-76.212.200.203-20111218065033

The Leviathans should be considered a exception as well, ImperiexSeed. There has been no discussion within the series whether the archangels or the Leviathans are more powerful than other, so we can only speculate. A far as we know the Leviathans could at least be on par with the archangels, so both could presumably destroy each other.