More than 2,000 years ago, the Lord of the Thirteen Families sacrificed himself and sealed the strongest devil of the Gonggro Family under the coffin with blood. But even so, the devil did not die. He was only sealed in the coffin. He could not turn over forever. The only thing that could open the coffin was the key of ancient destiny, legend, the key of destiny. It was the key of fate forged by the blood contract of the thirteen lords at that time. Only that key could open the coffin...

After creating the key, members of the thirteen clans chose to hide it in the most sacred place...