Kai Oku acts as Shou Hei Kun's trusted right-hand man and commander in the Qin military, simultaneously serving as a lecturer at Qin's Strategist Academy where he taught students including Ka Ryo Ten and Mou Ki. He joined Shou Hei Kun's academy at an unknown time, rising to become one of his most loyal vassals. A man in his 40s, Kai Oku possesses long black hair styled in two ponytails, a long goatee, and distinctive Manchu mustaches. He consistently wears elaborate robes, even over armor during military engagements, often maintaining a grim smile. His personality blends dutiful loyalty to Shou Hei Kun with a robust and occasionally teasing demeanor, evident in his interactions with former students during high-stress situations. His military involvement spans critical campaigns. During the Coalition Invasion, he monitored developments at the palace before being dispatched to investigate threats at Naifu. He later led nearly 100 elite soldiers, including 50 officers, to reinforce Sai’s defenses, commanding the north wall, advising against despair, and lightening the mood with banter toward Ka Ryo Ten and Mou Ki. In the State of Ai Arc, he was sent to Sanyou City to suppress unrest and uncover plots linked to the Queen Mother and Rou Ai, later aiding in quelling their uprising in Kanyou. For the Western Zhao Invasion, he co-planned the Gyou campaign strategy as one of four heads in Qin’s high command, led a decoy supply convoy, and briefly engaged Zhao general Shun Sui Ju in combat without serious injury. During the Nature Of Humanity Arc, he participated in a diplomatic mission to Han’s capital, Shintei, negotiating with King Ou An to secure the strategist Kan Pishi for Qin. Kai Oku's capabilities encompass strategy, combat, leadership, and diplomacy. A master strategist (intelligence stat 93), he identified vulnerabilities during the Battle of Sai and contributed to large-scale operations like the Gyou campaign. He demonstrates proficiency with a podao in battle (strength stat 85). His leadership stat of 92 underscores his effectiveness in commanding frontline troops and managing elite reinforcements. Politically, his selection as an envoy to Han highlights his diplomatic skill, further evidenced by a loyalty rating of 99 specifically toward Shou Hei Kun.