User blog comment:B214/Volume 21 info & spoilers/@comment-71.205.30.36-20160407022108/@comment-26345952-20160407234826

Well yeah she did. Rias did mention it about the seals once again. On Vol. 5 once Issei achieved Balance Breaker,Rias, before the rating officialy started, told him that because he achieved it it broke through the seals she implanted in him.