User blog comment:B214/Volume 23 discussion blog/@comment-178.244.146.161-20170524130013/@comment-30924344-20170524132748

Issei nor Vali for that matter, have the genes of Great Red or Ophis. Great Red just made a body for Issei and Ophis used her power to hold the soul and body together. Ophis blessed Vali to give him his Diabolos Dragon power, same with Issei.