User blog comment:Raze1313/Issei's Future Peerage/@comment-104.7.80.176-20150617023338/@comment-1359322-20150617025030

First, Ophis only lost her powers she didn't lose her divinity.

Second, Evil Pieces doesn't work on Gods, it has no relation to Issei or Ddraig. Their strength can't directly change the Evil Pieces to be usable to Gods.