User blog comment:B214/Question and Answers 6/@comment-190.164.227.239-20161201033222/@comment-29963364-20161203211937

Even when Issei got a new body made from Great Red's flesh using Ophis' powers, Ddraig said that Issei's base stats had increased a bit, but were still "shit."

Although, since Issei's body is such a unique and unprecedented case (a Mini-True Dragon Clone created from Ophis' power that reincarnated into a Devil), his potential is outside anyone's imagination.