Why is Sima Yulong called Chu Tianyou?

Looking for the queen mother In the film and television drama "Dragon Tour the World", Sima Yulong took the pseudonym Chu Tianyou. Accompanied by his affectionate brother, loyal Hou and confidante, and Ding Wuwei, who is proficient in medical skills and kind and funny, Sima Yulong was deeply loved by the people to find out the trace of the Queen Mother, and at the same time, secretly investigated the people's suffering and eradicated the remnants of the previous dynasty and corrupt officials. Sima Yulong, the protagonist in the costume TV series "Dragon Tour the World", 15 years ago was exiled for adultery and stealing the country. With the help of his superiors, he and Zhao Yu destroyed the usurper Ye Hong and regained the throne.