Huang Ling

Rei Ou is a Great General from the state of Wei. He is a part of the Seven Fire Dragons of Wei who are Great Generals who's abilities are on par of those of the Zhao Three Great Heavens and Qin Six Great Generals. He was also Go Hou Mei's teacher in strategic warfare. However internal fights occurred, and three generals including Rei Ou killed the other three generals, while Go Kei left the group. As a punishment, Rei Ou and the two other generals were in an underground prison for 14 years. (Source: Kingdom Wikia)