The modern soul travels back to Li Chengqian, the eldest son of the King of Qin. When he was eight years old, he won the elixir from Zuo Ci in a chess game, and cured old illnesses and extended his life for his mother's eldest grandson Wugu. On the day of the Xuanwu Gate Incident, he rushed back to the Prince of Qin's Mansion to fight off the soldiers of the Prince's Mansion to save his mother. Later, after discovering the prince's internal conspiracy, he broke into the Taiji Palace to wake up Li Yuan and promote his passing to the throne. Li Shimin, however, proposed to appoint Li Tai as the prince to avoid trouble.
