User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-23847729-20141105105810/@comment-1359322-20141110002905

Before that, currently all the efforts done to stop Qlippoth goes to D×D not just Issei, he isn't fighting alone you know. If the credits goes solely to Issei then why would others risked their lives just to get no acknowledgement, not that anyone in D×D cares much about such acknowledgement or stuff since they are doing it out of their own free will.