User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-92.228.150.7-20180331144820/@comment-120.188.5.229-20180331181836

Issei has mastered CxC since he has no problem using it anymore. I don't think CxC =Ddraig's full strength. I always see CxC as a form to enable Issei to gain access on Ddraig's hidden power like penetrate, longinus smasher and etc