Mythical Beast War

In the summer of the fourth year of the Republic of China, Guangdong suffered from continuous rain. The civil weir burst, floods overflowed, the houses became ruins, and people and animals drifted. At that time, my great-great-grandfather was appointed as the superintendent of the Guangdong Naval Academy, so he made friends and went to sea to provide disaster relief, hoping to control the flood and bring peace to the people. However, manpower is limited and heaven's power is boundless. Although we have great ambitions, they often fail to bear fruit, so we have to look back and sigh. On this occasion, the old Taoist secretly issued a secret edict to him: "This heavy rain and huge waves are definitely not a natural disaster, but caused by a demonic dragon. Unless the demonic dragon is suppressed, he will be starved to death like a mountain of bones..." So my great-great-grandfather borrowed a ship and went to sea overnight, loaded with guns and ammunition, determined to slay the dragon. Within a few miles of the sea, a sudden strong wind caused huge whale waves to hit the sky. In the valley of the waves, a black dragon appeared and disappeared. Its fins were ferocious and its body was several miles long... … All of this is recorded in the memoirs of my great-grandfather in his later years. Today, a hundred years have passed in a blink of an eye, disasters and famines occur frequently in the world, and there is a vague tendency of a tide of mythical beasts to come. Once the mythical beast appears, there will be disaster. And after a hundred years, who can bring up that dragon-slaying knife again, to slay dragons and gods?