Gaoshun is a middle-aged man of thirty-six who serves as the primary attendant, bodyguard, and adjutant to Jinshi, a powerful figure within the imperial court. He is a member of the prestigious Horse Clan, a family with a long history of providing personal protectors to the imperial bloodline. While publicly registered as a eunuch to allow him access to the inner palace, he is not one in actuality. Instead, he takes medicine that suppresses his male functions, a risk he accepts calmly, partly because he is already married with children and grandchildren. His public backstory claims he was punished and made a eunuch by a former empress, but this is a fiction to conceal his true status as the de facto head of his clan.

Outwardly, Gaoshun presents a calm, stoic, and highly capable demeanor. He appears as a quiet and earnest man, often looking tired from his hard work, and Maomao describes him as having a "healing" presence that provides a soothing contrast to the palace’s usual tension. Beneath this reserved exterior, he is extraordinarily considerate, detail-oriented, and deeply thoughtful, the type of person who quietly resolves problems before anyone else notices. He is a classic "beleaguered" straight man, constantly and silently cleaning up after Jinshi’s whims and extravagant schemes, which makes his exasperation a source of quiet humor. However, he is also capable of being frightening when genuinely angered and will not hesitate to reprimand his young master or his sons when they fail in their duties. Despite his serious image, Gaoshun has a surprisingly cute and wholesome side, including a fondness for cats and sweets. This is most notably displayed when he affectionately calls Maomao "Little Cat" and secretly spoils her with her favorite street buns.

Gaoshun’s primary motivation is his unwavering loyalty to the imperial family, particularly to Jinshi, whom he has served since childhood. Having known Jinshi, the current Emperor, Ah-Duo, and Lishu’s mother since they were all children, he feels both a professional duty and a deep, genuine friendship toward them. The Emperor himself assigned Gaoshun to protect Jinshi, the person most precious to him, over the objections of court officials who believed such a trusted officer was too important to waste on childcare. This history establishes Gaoshun as a stable and trusted parental figure in Jinshi’s life, someone who supports him unconditionally while also correcting his behavior like a guardian. In his role as the Emperor’s attendant and deputy, he also applies his sharp judgment and strategic thinking to help maintain peace and stability in the inner and outer courts.

Throughout the story, Gaoshun acts as a pillar of support for the main characters. He frequently urges the overworked Jinshi to rest and provides Maomao with valuable information or materials to help her solve medical and political mysteries. He functions as a voice of reason, trying to de-escalate the often chaotic dynamic between Jinshi and Maomao. His view of Maomao evolves from seeing her as a valuable pawn to be protected for her skills to developing a genuine, fatherly affection for her. This is evidenced by his quiet actions, such as being one of the first to encourage Jinshi to purchase her freedom from the Verdigris House. After Jinshi drops his own disguise and steps into his true public role, Gaoshun returns to his original duty as the Emperor's primary bodyguard, passing on the task of protecting Jinshi to his own son, Basen, continuing the Horse Clan's tradition.

Gaoshun's key relationships define his character. His bond with Jinshi is one of the most wholesome in the series, built on trust, long history, and mutual care, with Gaoshun serving as a rare paternal figure who does not use Jinshi as a political tool. His relationship with the Emperor is one of lifelong friendship and absolute confidence, and he shows no mercy to anyone who belittles the Emperor or those he treasures. At home, he has a wife named Taomi, who was Jinshi's wet nurse and manages the family affairs, and a daughter named Mamie, who resents him for his constant absence. His wife is the head of their household, a tradition of the Horse Clan where women manage internal affairs and governance while the men face the dangers of military service. This dynamic has given him a reputation as a "hen-pecked husband" who is easily bossed around by strong-willed women, to the point of developing a slight fear of them, though he remains at ease with Maomao.

Gaoshun is highly skilled in several areas. As a warrior, he is a formidable close-quarters combatant, with the ability to easily handle multiple opponents at once, a strength he has possessed since childhood. His skills are so renowned that he earned the moniker "camp crusher" or "formation breaker". He is also exceptionally intelligent and diligent, with a keen understanding of court policies and the political landscape, which allows him to navigate complex situations effectively. His sharp judgment, calmness under pressure, and practical decision-making make him an indispensable asset to his masters and a key figure in ensuring the security of the imperial family.