What is the relationship between Guan Yu and Cao Cao?

They are like enemies and friends, and they appreciate each other. Cao Cao appreciated Guan Yu's loyalty and superb martial arts, Guan Yu appreciated Cao Cao's benevolence and talent, and Cao Cao treated Guan Yu very well. Guan Yu once worked for Cao Cao, and he had no chance to be his own master. Guan Yu's loyalty will definitely not betray Liu Bei, and he will definitely be the enemy in the end.

Guan Yu, in the name of loyalty and righteousness, has a unique personal charm in the troubled times of the Three Kingdoms. The most famous is the five customs and six generals. Cutting Hua Xiong with warm wine is just a small experiment. Such a hero actually died of his own arrogance. When he stayed in Jingzhou, Lv Meng called, which really made the veteran feel a little incredible. His subordinates betrayed him, leaving him between Scylla and Charybdis, and finally died at the hands of Lv Meng.

Extended data:

In Guan Gong's whole life track, the decisive person is not Liu Bei and Zhuge Liang, nor the Han Dynasty, but Cao Cao. The appearance of Cao Cao laid a solid foundation for Guan Gong to become an emperor. In every historical event that people think Guan Gong is loyal and righteous, it is inseparable from Cao Cao. He is an indispensable person. On the basis of the three wishes in Taoyuan, with the help of Cao Cao, the spirit of Guan Gong was formed.

References:

Romance of the Three Kingdoms (Luo Guanzhong's Novel)-Baidu Encyclopedia