User blog comment:B214/Talk About What You Want! 2/@comment-24098614-20141012205808/@comment-73.178.133.185-20141016192633

@Astarothfan

Your description of Mutation Pieces is poor. A MP is a piece capable of reincarnating a powerful individual that would normally require multiple Evil Pieces by itself. They are "rare" and there is no guarantee that Issei would receive one, and if he did he might not want to use it depending on whether he could use a normal piece for Tiamat. What Otaku was asking was either what type of piece would be able to used (of course for someone of Tiamat's level, a Mutation Piece might very well be necessary) or which type would be best to use on her ability-wise. As for whether she would be "fantastic" for Issei or not is questionable because it seems Ddraig and her have a not so pleasant (unknown) history with each other.