User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-96.41.73.217-20150821174625/@comment-5961531-20150826005058

No there's not, however, I don't really need any to have a theory. As long as there is no evidence that blatantly contradicts my theory, I'm happy with that. It makes sense. No that's not the most likely. I'd rather have a reason as to why the Leviathans turned out the way they did, than simply because God was a "flawed creator". Also, a creator doesn't create one flawed creation and then move on to make their perfect work. If God was flawed as you say, he would have ended up creating more than one failed species before unveiling his masterpiece. At least my way, there is a logical and reasonable explanation as to why the Leviathans were evil.

Well it's not pure hyperbole... The implication is there, clear as day. The Darkness is an evil, corruptive and destructive force, and God's very first creations just happened to turn out as evil, corrupted beings. It hasn't been stated, it hasn't been written, but it makes sense regardless. If you're going to let lack of evidence get in the way of a theory, then you clearly need to learn the definition of a theory.

As for why the Leviathans corruption wasn't mentioned by Death, blame the latest writers. They only think in advance for the next series, but only remember the lore from the previous, completely forgetting about the others before. Continuity errors have occurred throughout the history of the show because of that, things don't always fit, but this latest story arc can still fit with everything we already know.