User blog comment:B214/Volume 23 discussion blog/@comment-31764731-20170726154553/@comment-175.139.34.125-20170727121458

CxC mastered is supposedly equivalent to Issei's DxD pre-nerfed.(More or less) Because his DxD pre-nerfed enables him to fight against Apophis equivalently who is stated to have achieve Heavenly Dragon-level.