User blog comment:Piyush Banerjee/Shin DxD 2 discussion/@comment-207.242.44.6-20181218202559/@comment-109.152.226.139-20181219030753

Rereading vol 12 where Akjuka was talking about putting Issei's soul In a Indentical clone body made from his parents DNA he said that is soul would take time to adjust to a indentical body, But is soul was not put in an indentical body it was put in a body made by two Dragon gods so his soul is having to adapt to a body vastly superior to his orginal body so it taking longer, Thats probably the reason soul is trying to absorb the power of Ophis from his body.