I Thought It Was a Divine Sculpture, but It Turned Out to Be a Myth

At the end of the Southern Song Dynasty, a historian traveled through time and became a general who was about to die for his country. He wanted to use modern knowledge to change his destiny, but he discovered that the truth of the world was far crazier than recorded in history books - the Mongolian cavalry was backed by an ancient fierce god, and the Song Dynasty's last trump card was a divine eagle sleeping in a sword tomb.