The story takes place a long, long time ago, when the coming of the Doomsday Judgment caused everything in the world to suffer a catastrophe. Although humans survived the disaster, the remaining number was less than 300,000. On top of the ruins, humans rebuilt their home—the predecessor of the Steel Metal Holy See. At the end of the century, faith has not been extinguished, and the church headed by the Steel Metal Pope rules this declining era.
However, the bloodline that was destroyed during the Doomsday Judgment was once again revived due to the opening of a sealed sarcophagus. Later generations of vampires call the people in the sarcophagus "the original people".
In order to survive, there were constant disputes between humans and vampires, and eventually the vampires gained the upper hand.
In order to prevent the two races from embarking on the road of common destruction, humans and vampires jointly established the "Thirteen Articles Act" with ecological balance significance. Blade was created by humans to defend the Act.
Lucia, a mixed race, his blood is the poison that can destroy the vampires; Osmond, who became the strongest, his long-cherished wish is to destroy everything and become the king of the scorched earth; Severn betrayed the Holy See and protected mankind all the time. The story will unfold around the three people in sequence.