User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-63.117.245.61-20120512193405/@comment-3045936-20120513174754

True and you also have to take something else into account. That its possible that while the souls increases his powers immensely he might not known how to use the souls power to their fulliest. Also, like Death said that while the Levianthans were destroying his vessal, he was also under all weight of all those souls, and while not as a big it was still problem stated by Death.