Li Shimin faked his death? Then I will be powerful enough to conquer the world!

In the fifteenth year of Zhenguan, Li Chengqian, who had traveled through time since childhood, discovered that Old Li had died early? Since Old Li had passed away, I would be the successor to the throne. Whoever dares to stand in my way, then let me teach you about the three camps I have established! However, Li Chengqian didn't know. Li Shimin actually wanted to use this method to determine which of his sons was suitable to be the successor because Li Chengqian was too obsessed with tricks, and also wanted to see what the Tang Dynasty would look like after his death? "What? Li Chengqian brought a large army into Chang'an?" "Where did he get the large army?" "You still want to purge the aristocratic families? What's so good about the aristocratic families...