Our Last Crusade or the Rise of a New World Novel Volume 15 was written by Kei Sazane with illustrations by Ao Nekonabe.

The invasion of Omen has been thwarted, and three of the Sovereignty’s princesses have joined forces with the Empire. But everyone decides what to do about the witches and the Calamity, Queen Mirabella hesitates to lend her aid. In order to face the truth, she asks Sisbell to use Illumination to recreate the past from thirty years ago...