User blog comment:B214/Question and Answers 6/@comment-9595671-20160714212150/@comment-24.113.252.213-20160715021234

In response to what B214 said earlier.

It is for that reason that I believe the Gods are left alone by the Evil Pieces. Ajuka knows the dangers of Gods being turned into Devils. The "Heaven System" of Christianity almost callapsed due to the Biblical God's death. And even though the "System" is being run by Micheal, it's not running the same way it used to (Holy-Demon Swords being proof).

As for whether Ophis can be reincarnated, I'm not sure. We could say that she can't because even a Mutation Piece can't handle her "Infinite" power, but we saw Issei obtain Ophis' "Infinite" power when he used DxD Mode. Regarding that, since 4 of Issei's Evil Pieces became Mutation Pieces to adapt to Ddraig's power, maybe his remaining 4 will become Mutation Pieces to adapt to Ophis' power.