User blog comment:B214/Question and Answers 6/@comment-207.242.44.6-20190418190602/@comment-10330822-20190419021219

Good question, ever since Issei unlocked the DxD G form, I've been worried that he is actually getting further away from Vali than continuing on this opposite form path.

The most logical guess would be rather than releasing Albion and fighting alongside it, he completely fuses with Albion at max power and uses boths power together.