Humans have been driven to extinction by "Beasts." The duty of fighting the Beasts fall to "Fairies," who are destined to use their powers to wield "Holy Swords" called "Carillons" and eventually meet their destiny of death. A
sole human being named Willem wakes up after several hundred years, and continues his fight against the Beasts.
This anime have an anime and manga
You can found source code on GitHub repository