User blog comment:B214/Question and Answers 6/@comment-168.28.180.30-20161020121416/@comment-10330822-20161021112544

They don't really touch on that. It is implied that they are working on ways for Angels to be turned using Evil Pieces, but that hasn't been shown to have happened yet. As of right now, you can't turn Angels using Evil Pieces, they aren't compatible.