User blog comment:B214/Volume 21 info & spoilers/@comment-191.82.149.185-20160704214534/@comment-24.113.252.213-20160707015527

So Issei is over a million times weaker than most other characters we've seen him fight against.

I know it's awesome that he can handle [Boost]ing his strength so much, but damn.

Instead of raising how much he can [Boost] his strength, he should focus on training to increase his base power.

Although if he does that, on top of how many times he can [Boost], he'll probably become OP as f**k.