Bo Zi

Shi Haku 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. However internal fights occured, and three generals including Shi Haku killed 3 of the other generals, while Go Kei stayed neutral. As a punishment, Shi Haku and the two other generals were in an underground prison for 14 years.

Shi Haku is said to be Wei's best spear wielder. His mastery with the spear is said to be so skilled that he is able to deal grievous blows to the point his enemies are incapable of noticing that they've been struck. It is also said that his skills didn't go rusty but rather he surpassed his form over the last decade despite being incarcerated for 14 years.

(Source: Kingdom Wikia)