Kenki Renka: Re:Zero kara Hajimeru Isekai Seikatsu†Shinmeitan

Long ago, a great war raged between the royal military of Lugunica and the demi-humans. On that battlefield, a noteworthy young warrior was born—Wilhelm Trias, dubbed the Sword Devil. But despite his skill with a blade, the boy would need to grow much more before he could become a true hero. This is the story of a legendary swordsman—and how he learned to love. (Source: Yen Press)