Ma Chao
Cao Cao led an army to Tong Pass to attack Ma Chao and the coalition, resulting in the Battle of Tong Pass. After both sides clashed in a few engagements, Cao Cao had talks with Ma Chao and Han Sui. Ma Chao thought highly of himself and secretly harboured the intention of dashing forth and capturing Cao Cao when they met. However, he did not dare to make his move when Xu Chu, one of Cao Cao's close aides, glared at him. Cao Cao later followed Jia Xu's strategy to sow discord between Ma Chao and Han Sui and make them become suspicious of each other. Taking advantage of the hostility between Ma Chao and Han Sui, Cao Cao launched an attack on the northwestern warlords and defeated them.