User blog comment:B214/Volume 22 spoilers/@comment-95.90.227.198-20170204105622/@comment-95.90.227.198-20170205094832

yeah your right but i think he has not hte potential to become very powerful, i think he is the only one that can become as strong as Great Red, Ophis (in full power) and Trihexa! Because i think Issei will defeat Trihexa  in the Future, he will train for it! Why ? Because he wants his Sensei, Brother in Law and all the others back, so he will train like an idiot to become as strong as these 3 (great Red, Ophis in full power and Trihexa) Ultimate Class Beings. And Issei is the only one that can reach this Level, but it will take Time but he will reach it:)