Lou Gui, courtesy nameZibo (子伯), was a hermit from Mount Zhongnan who lived in the late Eastern Han Dynasty. Lou later became an advisor to the warlord Cao Cao. During the Battle of Tong Pass against Ma Chao's forces, Lou advised Cao to build a large castle of ice in defense. Since then, Lou had been recorded in history as a good strategist, who was often praised by Cao Cao. However, Lou once spoke very rudely to Cao Cao, which resulted in his execution.