At the End of the Song Dynasty, Heading North, the World Was in Black Armor

The war between Mongolia and Jin lasted for nine years, and the Central Plains was in chaos. The young boy Fu Xiangbei carries the modern knowledge and last wishes left by his father, and leads the much-suspicious "reformed people" to form the Northern Returning Army. They built fortresses, made firearms, fought their way through the desperate situation in troubled times, and vowed to fight the Northern Expedition, just to regain their homeland and reshape the backbone of the Han family!