Why did Yongzheng Li Hong kill Liu Molin?

Li Hong didn't kill him, but Redstone sent an assassin to kill Li Hong. At that time, Liu Molin was with Li Hong, so he was eager to protect God and was killed by an assassin.

Liu Molin, Yong Zhengdi's hand-picked flower exploration; Yong Zhengdi cultivated it deliberately and placed high hopes on it, leaving it to the Minister of Armstocks of Emperor Qianlong. According to Li Hong, the fourth son of the emperor, Liu Molin died at the hands of evil to protect himself. In other words, he was killed by an assassin sent by the emperor's third son, Li Hong.

Detailed introduction:

At that time, Liu Molin was a cutting-edge minister deeply trusted by Yong Zhengdi and Li Hong, the fourth son of Emperor Chu Jun, who was in power and in charge of officials. Su Shunqing, on the other hand, was personally interceded by the favored Prince Huang Hongfa, and Yong Zhengdi personally arranged the wedding. After the fourth son of the emperor, Li Hong, attended the wedding in person, she married the love and Liu Molin that she never dreamed of. It can be said that she has reached the peak of her life and is satisfied.

Basic common sense, with Liu Molin's special status, must be closely attached to the protection of Emperor Zisi Li Hong in the face of the assassination of an assassin, rather than fighting in front of other guards. That is to say, when Liu Molin was killed, he could basically announce the fate that Li Hong, the fourth son of the emperor, was saved.