Li Jinzhi, a modern social animal, traveled through time and became a dude in Southern Chu. He just wanted to hang out every day: making a manned hot air balloon was trending as a joke.
He wanted to lie down and be a salted fish, but accidentally stirred up the rebellion of the second prince Huang and helped the prince to carry out agricultural reforms. Even the princess chased him and asked him "Why is the earth round?"
Others traveled through time to either fight for hegemony or farm, but he said: "Wait a minute, I'm really here to spend money, how can I unify the world by the way?"