Re:Zero Kara Hajimeru Isekai Seikatsu - Kenki Koiuta

A legendary swordsman and the woman he loves are at the heart of this story set in the world of Re:Zero. It follows Wilhelm Trias, later known as the Sword Demon, and the romance that begins amid war. In the past, the royal forces of Lugnica and the demi-humans wage a devastating war. On its battlefield, a legend is born: Wilhelm, the remarkable swordsman. The story recounts his life and the woman he loves, whose bond is described as a love between an evil spirit and a holy messenger.