User blog comment:Jopjopjop/High School DxD BorN episode 3 review/@comment-3290441-20150420184913/@comment-26209278-20150420211723

Well, he managed to reach BB when fighting Vali, he just didn't have the physical strength to keep it: the training with Tannin gave him the power to permanently unlock BB, just not the "Catalyst" to break it out. True, he did seem emotional when he was getting attacked by Kuroka, and it would cause BB in most hosts, but not our Oppai loving hero.