User blog comment:B214/Volume 23 discussion blog/@comment-26345952-20170318050112

So Issei has all of his 8 evil pieces mutated. Were they all mutated by DxD G or was it like last time representing Triaina and the Cardinal Crimson Promotion, cause this is my theory:

1 for the wyveins (the Crimson Extinct Dragonar is a Technique with them so I won't count it),

1 for Penetrate,

1 for DxD G, and

1 for the Scorching Flames of Blazing Inferno

the four majour power ups (or unlocks) that Issei had last arc.