The First Minister of the Sui Dynasty

What should you do if you unfortunately cross time? Li Tang, the school boy of Suixian Middle School, traveled through the Sui Dynasty and worked for the Sui Dynasty to recruit, select talents and govern the country, and assisted Yang Guang in ascending to the throne of emperor. He became brothers with Yang Guang, Yang Su, Li Yuan and others, met Li Mi, Yu Wenhuaji, followed Yang Guang, assisted the tyrant, and taught Li Shimin. As a result, he found that Yang Guang was different from what he imagined. Li Tang: "Your Majesty, I think the Grand Canal should be built now to connect the north and the south." Yang Guang: "It wastes people and money, so let's not do it." Li Tang: "Goguryeo is arrogant, and I believe that Goguryeo should be conquered eastward." Yang Guang: "The country has decided that we should rest and recuperate!" Li Tang: "I think we should patrol the north of the Great Wall from the west to frighten the north." Yang Guang: "It's so far away, let's stay in Kyoto!" Li Tang: "I think..." Yang Guang: "Huh?" He quoted Li Bai's poems and became the god of poetry in the Sui Dynasty. Finally, he discovered that Li Bai was actually his...