User blog comment:B214/Volume 23 discussion blog/@comment-78.48.65.206-20170426164843/@comment-190.160.185.214-20170427011825

Of course we can't know for sure, but at this point it's certain that DxD puts him on heavenly dragon class, otherwise he couldn't have beaten Apophis, who we know was heavenly dragon class (some may argue that Issei had a good matchup against Apophis, but the same was the other way around, so they were evenly matched)....now ASSUMING AxA is stronger than DxD (they could both be very well heavenly dragon class but different in the way the power is released) we have to ask ourselves what's stronger than a heavenly dragon, and the answer is a Pillar God like Indra or Shiva, so the comparison seem very plausible, and then comes ExE, which is certainly stronger than both DxD and AxA....here I'd put it in the middle ground between Pillar God and Dragon God, I still think it would be too much for Issei to be a Dragon God, that would mean reality itself could be altered by him, and he just has a fraction of Great Red's and Ophis' power