Dr. Nangong Yi, Yan Chixia, and Lan Xiulian. According to reading the novel "The Book of Iron Crane", the four guests are Dr. Nangong Yi, Yan Chixia, Bai Zhiying and Lan Xiulian, all of whom are world-renowned masters with outstanding talents and extraordinary personalities. Their appearance not only increased the interest and visibility of the story, but also made people have a deeper understanding of the style and characters of that era.