Li Shimin Faked His Death, Doesn't the World Belong to Me?

In the eighth year of Zhenguan, Li Shimin, the first emperor of the ages, discovered that the prince Li Chengqian liked masculinity. He was furious and wanted to depose the prince and used fake death as a test. The male protagonist's soul comes through and becomes Li Kuan, the second son of Li Shimin who died young. He is familiar with history and learns that none of Li Shimin's sons have a good end. He originally wanted to pretend to be stupid and wait until he leaves the fiefdom to become a free prince in this life. It turned out that there was a deviation in history, and Li Shimin ascended to heaven early! So... He was moved! Father's funeral? Then the young man has ascended the throne!