Re:ZERO Ex, Vol. 3: The Love Ballad of the Sword Devil (light novel) — Tappei Nagatsuki

THE WAR IS OVER, BUT THE WEDDING IS JUST BEGINNING...After overcoming more obstacles than any couple should have to endure, Wilhelm and Theresia can finally be together. The hopeful bride and groom soon discover, though, that wedded bliss comes with trials all its own. After a shaky ceremony and an overly crowded honeymoon, the Sword Devil and Sword Saint get to enjoy carefree days tackling mundane headaches and the impositions of their loved ones-but true danger lurks around the corner when the world cries out for the devil of the sword once more!