User blog comment:B214/Volume 21 info & spoilers/@comment-95.90.224.210-20160602194640/@comment-24.113.252.213-20160603020902

What I find irratating about Issei's character is how he carries himself around people.

Millicas, Sirzechs and Grayfia's son, respects Issei like an older brother and sees him as a better role model than Satan Red (Sirzechs), yet Issei still talks to him like he's lucky to be in the same building.

When someone (Sona, and Ddraig) mentions that Euclid is far superior to Issei in terms of using the Boosted Gear despite it being an inferior replica, Issei suddenly starts shaming himself to the point he needs encouragement.

I hate how everyone, including Issei himself, constantly regard him so lowly despite how far he's come and what he's accomplished. I'm not saying he should be like Vali (an arrogant ass), and being humble is a quality I like about him, but he should at least have the confidence to not get hurt by words, or bow to a kid (even if he is the son of a Satan).