Teacher from Hometown: from Black Iron to Heaven

Thousands of years of history are over, and the human race's federations are in charge of the galaxy. In this world, all the awakened legions of all races are drawn by blood, and having an army for a lifetime is a supreme miracle. Lin Yan is the only soul from the earth in this universe. During the awakening ceremony, he did not activate the alien divine army or awaken the powerful federal brigade. He only awakened the humblest and most inconspicuous mortal army. No one knows that this seemingly ordinary army is his "relatives" from his hometown of Earth. It is the only relative and the only root he can rely on in this strange universe. From mortal infantry to elite armies; from line-filling corps to interstellar masters. Use the Earth's military soul as your bones and the federal galaxy as your chess piece. Let's see him, with the master of his eternal hometown, travel across the galaxy, conquer the universe, and become famous in the heavens!