An orphan who raised his younger sister Cao Xiaolan single-handedly. He brought his sister to a border town while joining the military camp. He was Liu Zhezheng's close brother-in-arms who faced life and death together. He was severely wounded saving Liu Zhezheng during an ambush. Despite his sister's obsessive behavior, he remained devoted to her, eventually becoming so exhausted he could only check on her from outside the door. He died from wound infection caused by Cao Xiaolan's deliberate neglect and sabotage.
