Xiaren traveled to the Tang Dynasty and became Li Chengqian. He came to Tianzhu Mountain and met Zuo Ci and practiced for two years. After returning to the Tang Dynasty, he rescued his mother's eldest grandson Wugou during the Xuanwumen Incident. Before he came to Li Yuan, he gave up the crown prince to Li Tai. Finally, without Li Shimin knowing, he founded the Tang Dynasty's first intelligence building "Tingfeng Tower" and the Tang Dynasty's first secret guard "Shadow".
