Fan Xian was sent to Northern Qi.

Fan Xian's purpose in going to Northern Qi was to exchange for the imprisoned Yan Bingyun and complete the four missions Chen Pingping had given him. Fan Xian successfully ensured that Yan Bingyun returned safely and took over a position in the First Bureau. In addition, Fan Xian had also established a good relationship with the Northern Qi Imperial Advisor Ku He's disciple, Haitang Duoduo, and the Northern Qi Emperor, Zhan Doudou, to control the smuggling channels from the palace treasury to Northern Qi. Fan Xian had faced great danger on his diplomatic mission to Northern Qi, but in the end, he had successfully completed his mission.

Fan Xian's relationship with Northern Qi was based on interests and safety considerations. Fan Xian used his wisdom and caution to deal with the relationship between Qing Kingdom and Northern Qi, displaying superb wisdom and caution. The relationship between Fan Xian and Northern Qi was built on the basis of mutual use and cooperation. Fan Xian and Northern Qi worked together to let his sister Fan Ruoruo become Ku He's disciple and send his brother Fan Sizhe, who had committed a crime, to Northern Qi to take over the palace treasury smuggling. This was also to prevent the Qing Kingdom's hostile forces from attacking him. Fan Xian more or less had Northern Qi's cooperation and assistance in the important matters of the Qing Kingdom.

The search results did not provide a clear answer as to why the Northern Qi Emperor, Zhan Doudou, had chosen Fan Xian as his partner. In " Celebrating Years," Fan Xian established a connection with the Northern Qi Emperor, Zhan Doudou, and the Northern Qi princess, Haitang Duoduo, through a series of actions and exchanges. Fan Xian had initially gone to Northern Qi to save Yan Bingyun, who had been betrayed by the Eldest Princess. He had also helped resolve some problems while in Northern Qi. Fan Xian's identity and status allowed him to protect Zhan Doudou's true identity while he was in Northern Qi. The specific reason why Fan Xian and the Northern Qi Emperor had come together might gradually be revealed as the plot developed.

Fan Xian was in Northern Qi for many reasons. First of all, Fan Xian's decision to send Fan Sizhe and Fan Ruoruo to Northern Qi was to temporarily hide from the limelight. In reality, Fan Sizhe had not been able to return to his homeland in Jingdou for many years. Fan Xian's connections in Northern Qi were good. He had even recognized Haitang Duoduo as his " sister-in-law." This gave him a backer and more friends in Northern Qi. In addition, Fan Xian himself liked to do business. He planned to take charge of the palace treasury after Fan Xian's wedding, so Northern Qi's business activities were very important to him. Fan Xian also realized that he was not alone in Northern Qi. He received the love and care of Fei Jie, Fan Jian, Chen Pingping, and others. Although they were not blood relatives, their love and care for Fan Xian was meticulous. In short, Fan Xian was in Northern Qi to find his value in life, to obtain freedom and warmth, and to display his ability and determination.

Fan Xian had sent Fan Sizhe and Fan Ruoruo to Northern Qi after weighing the pros and cons. Fan Xian had hoped to temporarily avoid the limelight, but he hadn't expected Fan Sizhe to not be able to return to Jingdou for many years. Fan Xian's relationship with his family was not close in his previous life, but after transmigrating, he realized that he was not alone. There were many people who gave him love and care. The Northern Qi Emperor and Fan Xian came together because they had common interests and emotional entanglements. Fan Xian's operation in Northern Qi was to rope Duoduo in and prevent her from confronting the diplomatic mission. Fan Xian saw the Northern Qi Emperor kneel because he represented the Qing Kingdom as an envoy. According to the principle of diplomatic equality, if he did not kneel, the Northern Qi envoy could not kneel before the Qing Emperor. As for the reason Fan Xian and the Northern Qi Emperor cooperated in smuggling, the television version did not go into depth. However, in the original work, smuggling was very important to Fan Xian. After Fan Xian returned to the diplomatic mission, he used Northern Qi's Eldest Princess to say that he was Sigu Jian in order to return to the diplomatic mission reasonably. Fan Xian did not see Lin Wan 'er after he returned because of the marriage between the Northern Qi Princess and the Qing Prince. As for why Fan Xian had Fan Sizhe and Guo Baokun go to Northern Qi, it was probably to tell the Northern Qi people that the spies of the Qing Kingdom were no longer a threat and to protect the spies hidden in the dark.

Fan Xian's decision to go to Northern Qi was based on many considerations. First, Fan Xian wanted to protect Fan Sizhe and Fan Ruoruo. Sending them to Northern Qi was to temporarily hide from the limelight. Fan Xian deeply understood the importance of family. They gave him warmth and love. Fan Xian had also completed one of the four tasks Chen Pingping had given him, ensuring that Yan Bingyun returned safely and took over the First Bureau. In addition, Fan Xian had a special relationship with the Northern Qi Emperor, Zhan Doudou. She was Fan Xian's lover, and the Northern Qi wangfei, Si Lili, was Fan Xian's lover. Fan Xian's identity in Northern Qi was relatively safe. He could bring benefits to Northern Qi. Furthermore, Fan Xian's existence was controllable for Zhan Doudou. In short, Fan Xian went to Northern Qi to protect his family, complete his mission, protect his personal interests, and maintain his relationship with Zhan Doudou.

There were several reasons why Fan Xian and the Northern Qi Emperor had come together. First of all, Fan Xian and the Northern Qi Emperor Zhan Doudou were in a cooperative relationship. Both sides had obtained what each other needed. Secondly, the relationship between Haitang Duoduo and Si Lili, as well as Fan Ruoruo becoming Ku He's disciple, made Fan Xian's relationship with Northern Qi even closer. In addition, the Northern Qi Emperor, Zhan Doudou, was a woman. He had physical contact with Fan Xian, so Fan Xian naturally had to consider his woman. In the end, Northern Qi poured a great deal of energy and support into Fan Xian. In short, the relationship between Fan Xian and Northern Qi was based on cooperation, mutual benefit, and affection.

Fan Xian went to Northern Qi because of many considerations. First, Fan Xian wanted to protect Fan Sizhe and Fan Ruoruo. Sending them to Northern Qi was to temporarily hide from the limelight. Fan Xian deeply understood the importance of family. They gave him warmth and love. In addition, Fan Xian had completed one of the tasks Chen Pingping had given him in Northern Qi, ensuring Yan Bingyun's stability. Fan Xian met many people in Northern Qi, including the Northern Qi Emperor, Zhan Doudou, and the Northern Qi Princess. They became Fan Xian's friends and lovers. Fan Xian's experience in Northern Qi had also allowed him to obtain wealth and status. In short, Fan Xian went to Northern Qi to protect his family, complete his mission, make friends, and pursue his own interests.

Chen Pingping had withdrawn the Black Knights when Fan Xian had gone to Northern Qi because of the Qing Emperor's orders. The Qing Emperor hoped that no one would protect Fan Xian because he believed that Wu Zhu, who was behind Fan Xian, was his greatest threat. The Qing Emperor guessed that Wu Zhu was behind Fan Xian's many attacks. After not seeing him for many years, the Qing Emperor was not sure if Wu Zhu had improved. In addition, Wu Zhu had many secrets. The Qing Emperor was very curious about them. The Qing Emperor's goal of withdrawing the Black Knights was to lure Wu Zhu out. He believed that Wu Zhu was most likely to appear when Fan Xian was in danger. As Fan Xian's protector, Chen Pingping carried out the Qing Emperor's orders and withdrew the Black Knights.

At first, Fan Xian thought he had spent the night with the Northern Qi wangfei, Si Lili. In reality, he had slept with the Northern Qi empress, Zhan Doudou. Later, when Fan Xian met Zhan Doudou again, he discovered her true identity. This discovery rekindled their relationship and eventually led to the birth of their child. So Fan Xian finally knew the true identity of the Northern Qi Empress.