User blog comment:B214/Volume 23 discussion blog/@comment-172.56.16.22-20170422032237/@comment-202.44.34.137-20170422043622

Issei has an extraordinary growth rate. When they finally face each other, Issei in BB form may be able to knock Rias out with one hit. It took only few month for Issei to surpass Rias in overall strength anyway.