I'm loving this story and it's very interesting how the intro turned Japanese mithology into pseudohistory.
By the way, are we sure the Supernatural tag fits here? Both "gods" and "sorcerers" are explicitly described as a mix of metaphors and propaganda; and "demons" are regular humans too, they just were selectively bred for strenght and ferocity. As for their descendants it looks more like a recessive condition that causes anger management issues, which "sorcerers" treat with anxiolytic smokes. I guess I'm going to propose removing the tag unless further releases suggest otherwise.