Xiaren traveled through the Tang Dynasty and became Fang Xuanling's son Fang Yiai. When he learned at the beginning that he was going to marry Princess Gaoyang, he immediately asked Fang Xuanling to break off the engagement. Unexpectedly, this scene angered Li Shimin. Li Shimin originally wanted to teach Fang Yiai a lesson, but he never thought that Fang Yiai had come up with advanced equipment far beyond this era. Now Li Shimin wanted Fang Yiai to be his consort.
