During the Three Kingdoms period, the Five Tiger Generals were a group of valiant and warlike generals who repeatedly clashed Cao Cao's army. Of these five generals, who caused the most damage to Cao Cao?
First, let's take a look at Guan Yu. Guan Yu besieged Xiangyang, flooded the Seventh Army, and captured Yu Ban and Pang De, but was eventually defeated by Cao Ren and Xu Huang. His attack did put a lot of pressure on Cao Cao, but it did not cause fatal damage to Cao Cao.
Then came Zhang Fei. Zhang Fei fought against Cao's army on several occasions and defeated Cao's army at Changbanpo. However, most of his attacks were rapid marches and surprise attacks, and failed to inflict lasting damage on Cao Cao.
Zhao Yun had fought Cao's army several times and rescued Huang Zhong in the Battle of Hanshui, but his attacks did not cause much damage to Cao Cao.
Ma Chao once defeated Cao Cao in the Battle of Tongguan, but was later forced to take refuge in Liu Bei by Cao Jun**. Although his attack posed a great threat to Cao Cao, it did not cause substantial damage to Cao Cao.
Finally, there is Huang Zhong. Huang Zhong killed Cao Cao's general Xiahou Yuan in the Battle of Dingjun Mountain, which was undoubtedly a major blow to Cao Cao. Xiahou Yuan was Cao Cao's close general, and his death undoubtedly caused great psychological damage and military losses to Cao Cao.
To sum up, although the five tiger generals had all robbed and killed Cao Cao, Huang Zhong's killing of Xiahou Yuan in the Battle of Dingjun Mountain caused the most damage to Cao Cao. This battle not only deprived Cao Cao of an important general, but also dealt a big blow to the morale and command system of his army.