Traveling Through Time and Again, Li Yu Revitalized the Southern Tang Dynasty

[No system + double time travel + few emotional lines] Li Yu looked at the familiar scene in front of him. He didn't expect that he had traveled back in time, but this time he would not be as cowardly and incompetent as before. He used the necessary knowledge of time travel that he had learned in modern times to successfully change the history of the Southern Tang Dynasty. He unified China on behalf of the Song Dynasty, and at the same time actively expanded outwards...