User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-77.182.213.61-20180706173845/@comment-86.145.209.212-20180710151903

Personally I can't see why Issei's base power can not surpass Satan class power since his has Ophis power overflowing into is Soul, dormant Great Red power and in his body and his Evil pieces have both Ddraig and Ophis power flowing into them,

Everything that makes up Issei is slowly being changed by powers that surpass Satan level power.