User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-24.19.250.159-20120510031357

In the latest episode it said that metatron (lol at Sam's megatron) kept record of God's creation. And given that the "word of God" in the latest episode mention the leviathans I'm assuming the arcangels, or at least Metatron was before the leviathans.

Or it could just be that Metatron recorded "How" to kill the leviathans after he was created (he take the records of creatures even before himself after he was created).