"How deep is the abyss called suffering? Is it the same as the night sky, dark and endless?" Goddess Calypse asked as the world was on the verge of collapse. In the past, Michel had also asked such a question. Born from the Sinclair Family, a family that created many great summoners, but he has no talent for summoning even the lowest-tier spirits. That bitter reality, made him have to accept bad things from his entire family, even from his own mother. They don't know that he is a sword of vengeance. When Michel gave up on becoming a summoner, a mysterious book suddenly appeared and he summoned the demon king's daughter. "Abyssal mark, that birthmark will only appear when the world is about to end!" When the world is on the verge of collapse, Michel as the ruler of Greatland is finally faced with a choice. Will he choose to save the world by letting it crumble? Or, will he choose something futile?