User blog comment:B214/Question & Answers 5/@comment-207.87.40.22-20150521152829/@comment-26209278-20150523075945

I feel that Rias would lose to Issei and Kiba because 1) of their growth, they are very strong, and 2) Because of their speed, they would be able to close a gap before Rias could hit them with magic. Besides from that, Rias would probably annihalate both of them.