Ninth Door

Doors are used for isolation. Broadly speaking, there are two worlds in front of and behind the door. There are also portals between the huge cosmic worlds, and there are heavenly demons inside the doors, which are also called heavenly demon gates. The world corresponds to people, and people have great treasures, which are called secret doors, with a total of eight doors from head to toe. Those who break the boundary may have a ninth door in their bodies.