User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-31764731-20180317181830/@comment-86.174.153.16-20180318020553

Unlikely true DxD  is to powerful for him to handle since he can only handle the downgraded version for a few minutes at a time. Issei seems to me to be in a position where he needs a power up to hamdle the extreme power of the last power up.