User blog comment:B214/Question and Answers/@comment-80.117.124.108-20130101142245/@comment-5882552-20130127034446

Personally, I don't think Issei's "curse" is lifted. After all, the effects of Juggernaut Drive affected his life/soul, and not his body. Since the events in Volume 12 only gave Issei a new body, his old soul still remains, so the Juggernaut curse could still be within. However, it's still possible that: 1) Ophis, Great Red and Ddraig performed some miracle to heal Issei's soul or 2) Great Red's dragon powers overpowered the curse of Juggernaut, thus lifting Issei's curse. If all fails, there's still Koneko's "fast method"....