User blog comment:Crimson and Darkness/Volume 25 discussion blog/@comment-32252462-20180321143728/@comment-200.137.65.109-20180321161637

It's simple. Issei is faster than Kiba by quite a margin. He didn't get any development whatsoever in the past volumes until now. If Kiba can't hit Issei with one of his holy swords, he's done for. Kiba has yet to master using Gram, but Issei already has pseudo DxD. Sorry if I wasn't convincing enough, but that's how it is