User blog comment:B214/High School DxD BorN Episode 10 Review/@comment-182.69.39.172-20150609175230/@comment-97.103.233.248-20150610035345

Issei isn't at vali's level yet at this moment in the anime.

Vali has complete juggernaut drive(even though it's only for a short time)

Vali is stronger even without divine dividing at this point in time.