User blog comment:Jopjopjop/Volume 18 Spoilers/@comment-3325617-20140703152403/@comment-1359322-20140703152831

No Issei's Pawn Pieces would retain, even if Issei becomes a High-class Devil, Issei would still be Rias' Pawn, like how Tannin is still Mephisto's Queen even after Tannin reached Ultimate-class.