High School DXD, Vol. 12 (Light Novel): Supplementary Lesson Heroes Volume 12

NO MORE ISSEI.The resident pervert of the Gremory Familia is gone. Kiba tries to step up in Issei's place while Rias and the others mourn, but there's only so much he can do alone, and even he feels the weight of his friend's absence. Meanwhile, the underworld is beset by the greatest threat it has seen since the war. Hades and the Hero Faction have made their move. Will the demons be able to survive without the Breast Dragon Emperor?