User blog comment:B214/Volume 21 info & spoilers/@comment-71.205.30.36-20160407022108/@comment-213.120.234.109-20160407172510

That makes sense. I always wondered what happened to those "seals" Rias put on Issei, coz she mentions them in volume 2 before the rating game with Riser but then they never got mentioned again. Made me wonder if they were still in place, guess not now.