User blog comment:EmpyreanSmoke/Leviathan VS Archangel/@comment-188.4.147.206-20140826134718/@comment-24834479-20140828005149

Many times humans have been shown to be able to physically move the leviathan, just like Castiel did. And the point of negating their powers is so they can't fly away, or see that they are Leviathan.