User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-26285797-20150721203748/@comment-79.31.173.86-20150722234759

Please, Issei used Ophis power (her own power, not the power that he has received by her when she made his new body)! Not only his own power! So Diabolous Dragon real power is not that he used against Rizevim! It's like when he used Great Red power to use a gigantic balance breaker.