Two hundred years ago, an alien civilization invaded. The three realms were invincible, the fairy world was destroyed, the underworld was severely damaged and on the verge of collapse, and the human world was destroyed!
In the end, Tiandao desperately killed the domain lord of the civilization outside the territory, and drew a boundary between the outside world and the Three Realms. A natural battlefield was formed within the boundary - the Land of Dao Collapse, and the powerful in the mortal world were not allowed to enter!
Then the way of heaven collapsed, and the remaining people in the human world learned the inheritance of the immortal world and the underworld and built the endless Great Wall at the boundary of the barrier. Within the barrier, they launched a hundred-year war with evil demons outside the territory.
Not bad. . .