Our Last Crusade or the Rise of a New World, Vol. 13 (light novel) — Kei Sazane

In the aftermath of Elletear's attack, nothing is certain about the war between the Empire and the Sovereignty. Kissing surrenders to Iska to avenge her uncle, and the two join up with Alice and the others to travel to a forbidden land in search of answers. There, they learn the truth of the astral swords, the calamity at the center of the planet, and the terrible future that awaits…