User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170412031517/@comment-1.0.201.117-20170412091132

Currently, Issei can be considered as the most powerful red dragon emperor ever exist. using "weakest" to describ him is no longer correct.

I think that "the least talented" is a more accurate description for Issei since he used to be a complete nomal human before being reincarnated.