The main antagonist of the first arc of High School DxD: Revival, "As a Warrior, As a Hyoudou Warrior!" and he is probably very strong, as he killed Giichi Asmodeus, and Giichi Asmodeus is still afraid of him. Although, in Volume 2, it is proven to be wrong. Although, further than that, it was hinted that he didn't actually manage to kill Giichi Asmodeus. Plus, it was stated that Giichi Asmodeus actually lost on purpose.