The demon Vespela, who was imprisoned by the Black Tower for three hundred years, broke the seal due to the tragic death of her old friend Elara and came to the human world to protect the two children she left behind. The once cold and bloodthirsty demon experienced love, hate, sorrow, and joy in the human world, established a night home to protect the oppressed and weak, devoted his magic to guarding the entire valley, crossed long years, and finally became revered as the mother of the dark night by the world.