User blog comment:B214/Volume 23 discussion blog/@comment-206.224.253.186-20170420231523/@comment-30048084-20170421200057

Issei won't learn magic because it contradicts his character. Issei doesn't use long range techniques often and those that he do are typically highly destructive (Crimson Blaster, Longinus Smasher, Infinity Blaster), Dragon Shot is the exception and Issei is learning how to manipulate it like Sirzech's Ruin the Extinct.

The only ability I think Issei can learn that matches his character would maybe be Senjutsu but that could also be a bit of a stretch.