What's the Name Without a Tune?

At the beginning of the universe, the great god Pangu created the world and transformed the world with his body. So far, the world has its original appearance. Shushan is located at the center of the world and is responsible for conquering demons. However, it was unexpectedly secretly invaded by demons and almost destroyed here. Various sects from the human world come to help. Can the demon world be defeated in the end? What is the protagonist's position?