User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-96.41.73.217-20150821174625/@comment-5110811-20150825235216

There was no hint at all that the Leviathans were ever good to begin with. Not one mention of it on the show. Death called them the "first beasts." How else were they supposed to act? Most likely, God is a flawed creator during the beginning.

Yes, we are both speculating. But your theory on the Darkness corrupting the Leviathans is just pure hyperbole. There's no implication of it at all. Why?

Because Death should have mentioned the Leviathans in his speech to Dean, when he was explaining to him about the Darkness, simply because, according to your theory, the Leviathan's supposed corruption should be the major deciding factor in determining God to create a different set of race specifically tailored made in helping him fight off the Darkness. So the Darkness will never corrupt any of his other creations ever again.

But he didn't mention them at all. And Unfortunately, as we all know, Death bites the dust in the end.