Chen Gong

Chen Gong started his career under Cao Cao but he later defected to Lü Bu and became his adviser.

Romance of the Three Kingdoms
In the 14th-century historical novel Romance of the Three Kingdoms by Luo Guanzhong, Chen Gong was given a positive makeover. He was said to have given up his official post to follow Cao Cao, who was then on the run after an attempted assassination on Dong Zhuo, a tyrannical warlord holding the emperor hostage in the imperial court. However, he left Cao Cao when he thought the latter was not an upright man either.