User blog comment:B214/Volume 23 discussion blog/@comment-86.143.86.100-20170203180136/@comment-31137559-20170204050445

Like I said Issei is already pretty powerful and just needs more combat experience and time. Something like that this late in the series would be lame. Think about the Boosted Gear Scalemail like wearing armor in a way. Would it be faster for you to develop the strength to be able to don the armor or would it be faster to don the armor and have yourself get used to it and have your physical abilities improve every time you wear it? Now while the scalemail does boost his power a lot, it does rely on Issei's stamina and physical strength. And with each use, he's able to improve his physical abilities and stamina and improve after each use. And the Boosted Gear is his normal power. He has had it since birth. And I believe Boost doesn't work that way. Each time Issei boosts that's some of his energy being used up. And it increases his power, not his stamina. If he was able to do that he would be doing it in every fight. The abilities of Issei's Boosted Gear rely on Issei's energy himself. It's not like Issei has an unlimited number of boosts he can perform. And like I said Issei has already developed his Balance Breaker past subspecies and Abyss side. The only other transformation I can see coming after that is Issei turning into a dragon. Issei's sacred gear is irregular where his is a combination of both. Like I said, doing something like that this late in the game would just be an asspull and would kind of be shitting on Issei's unnatural growth up to this point.