Song of Mountains and Seas

The unknown spiritual sea is the origin of spiritual energy in this world. The spiritual sea rises and falls periodically, with tides occurring once every thousand years. Thousands of years ago, monsters ravaged the earth. There were warriors who used magic, heavenly phenomena, and earth to subdue dragons and tigers. There were magicians who shook mountains and reclaimed the land. Human beings paid a huge price to drive the monsters back to their lair. A cross-cutting mountain range and a vast sea separated monsters from humans. Now that the tide is coming again, how can the world be settled this time, and what kind of joys and sorrows will happen?