Talk:Seekvaira Agares Peerage/@comment-26042226-20151128035136/@comment-26042226-20151128090935

I think in case of Issei, the 4 mutation pieces represented the Rook, Bishop and Knight modes of the Cardinal Crimson Promotion, Im sure thats why they changed into Mutation Pieces..

And I just checked on the DxD Wiki that normal pieces can change into Mutation Pieces, but they are very rare, as 1 in 10 Devils possess the piece.