Our Last Crusade or the Rise of a New World, Vol. 7 (light novel)  (English, Paperback, Nekonabe Ao)

The Nebulis Sovereignty is up in flames. For the first time since its founding, the witches' paradise is being raided by Imperial forces. It's Imperial solider against Sovereign witch-Saint Disciples versus Purebreds. As war indiscriminately obliterates all, Iska's unit engages in combat with the Hydra, and a new witch begins to make her move as paradise falls.