The reason Yan Bingyun killed Fan Xian was to protect the safety of the Qing Kingdom. When Fan Xian went to Northern Qi, he went to the Third Bureau of the Overwatch Council. This caused the Qing Emperor to worry. The Qing Emperor knew the importance of Yan Bingyun, so he sent Fan Xian to Northern Qi to rescue him. In order to safely return to Jingdou, Yan Bingyun and Fan Xian plotted this assassination.
Fan Xian had not been killed by Yan Bingyun. In the drama " Celebrating Years," Yan Bingyun stabbed Fan Xian, but it was not fatal. In reality, there had always been a grudge between Fan Xian and Yan Bingyun. It was mainly because Yan Bingyun had mistakenly thought that Fan Xian had killed Teng Zijing, and that Teng Zijing had actually sacrificed himself to protect Fan Xian. However, the reason Fan Xian chose to fake his death was still unclear. According to speculation, Fan Xian might have made this decision to protect the Qing Kingdom. In short, the relationship between Fan Xian and Yan Bingyun was complicated. They might have a relationship of cooperation and conflict.
There was no clear answer as to what happened after Yan Bingyun killed Fan Xian. The original novel " Celebrating Years " did not reveal the specific plot after Yan Bingyun assassinated Fan Xian. However, according to some explanations and guesses, after Fan Xian was stabbed by Yan Bingyun, Yan Bingyun gained the Second Prince's trust and pretended to rely on the Second Prince to become Fan Xian's spy. After Fan Xian was rescued, he and Yan Bingyun discussed a plan. While Fan Xian was in Northern Qi, he revealed his guess to Yan Bingyun. On the way back to the Qing Kingdom, he asked if Yan Bingyun would help him, but Yan Bingyun did not answer. Based on this information, we can speculate that Fan Xian and Yan Bingyun might work together to break out of this situation, but the specific follow-up plot has not been clearly revealed.
As for why Yan Bingyun killed Fan Xian in the original work of " Celebrating Years," there was currently no definite answer. The specific reason and background would be revealed in the second season.
Yan Bingyun killed Fan Xian to cooperate and fake his death to protect the stability of the Qing Kingdom. After Fan Xian learned of the Second Prince's plot, the Second Prince gave him two choices. Either he became the number one official of the Qing Kingdom or he died on the way back. In order to avoid turmoil in the Qing Kingdom, Yan Bingyun stabbed Fan Xian in the back when he was faced with threats and promises, causing Fan Xian to fake his death. This was to facilitate the smooth escape of Fan Xian and the diplomatic mission and to protect the stability of the Qing Kingdom. There were many possibilities for the development of the plot. For example, Fan Xian faked his death and reached an agreement with Yan Bingyun, or Fan Xian was rescued by someone.
In the original work," Celebrating Years," Yan Bingyun killing Fan Xian was a plan that the two had discussed beforehand. Fan Xian faked his death to protect Fei Jie, Fan Sizhe, and Teng Zijing's son. He wanted to prevent the Second Prince from using them to threaten Fan Xian. Before Fan Xian went to Northern Qi, he had obtained a precious robe that could defend against the damage of a blade. The specific reason and background would be revealed in the second season.
There was no clear answer to the plot after Yan Bingyun killed Fan Xian in " Celebrating Years." The original novel did not reveal the specific plot after Yan Bingyun assassinated Fan Xian. However, according to some explanations and guesses, after Fan Xian was stabbed by Yan Bingyun, Yan Bingyun gained the Second Prince's trust and pretended to rely on the Second Prince to become Fan Xian's spy. After Fan Xian was rescued, he and Yan Bingyun discussed a plan. Therefore, the details of the aftermath of Yan Bingyun killing Fan Xian were still unclear.
In the original work, Yan Bingyun killing Fan Xian was a plan the two had discussed beforehand. Fan Xian faked his death to protect Fei Jie, Fan Sizhe, and Teng Zijing's son. He wanted to prevent the Second Prince from using them to threaten Fan Xian. Before Fan Xian went to Northern Qi, he had obtained a precious robe that could defend against the damage of a blade. The specific reason and background would be revealed in the second season.
There was no definite answer to the question of why Yan Bingyun killed Fan Xian in the original work. Some possibilities were mentioned. One of them might be for the safety of the Qing Kingdom. Yan Bingyun believed that Fan Xian's actions might be detrimental to the Qing Kingdom and chose to betray Fan Xian and rely on the Second Prince. The other possibility was that in order to protect himself, Fan Xian and Yan Bingyun had discussed a plan to fake their deaths in advance to deceive the Second Prince. The specific reason and background would be revealed in the second season. Therefore, there was no definite answer to this question.
In the Qing Yu Nian novel, the plot of Yan Bingyun killing Fan Xian happened in chapter 15.
There were many possibilities for the plot after Fan Xian was killed by Yan Bingyun. Fan Xian might fake his death and reach an agreement with Yan Bingyun to break the situation. Yan Bingyun gained the Second Prince's trust and pretended to rely on the Second Prince to protect Fan Xian as a spy. In addition, after Fan Xian was stabbed by Yan Bingyun, he did not really die. Instead, he was rescued. However, the specific plot development and ending required the audience to continue watching the series to understand.