User blog comment:B214/Volume 22 spoilers/@comment-24173056-20160611141433/@comment-24.113.252.213-20160613214814

He'll at least register as a King and get his Evil Pieces, right? That's the most important part about him becoming a High-Class Devil (aside from being able to marry Rias without much consequence).

I know Issei is already engaged to Rias (without him even knowing), but I really hope this gives him the courage and confidence (balls) to propose and make it official on his own.