What Zhu Di is guarding the country is the power beyond nature.
After guarding the country, he found someone to make 13 treasures and a sword named Zhenyue.
At the end of the Ming Dynasty, Zhu Youjian did not commit suicide but fled south with the Thirteen Treasures.
After Li Zicheng attacked the city, Zhenyue was destroyed into two short blades.
Due to the loss of 13 Treasures and Zhenyue, the natural power was unsealed and no longer restricted. It came to the world and did evil at will.
The protagonists have various abilities to save the world.