8 years old / Male Race: Spirit First person: I (soft, polite) Second person: you / name True identity and age: A black cat spirit born from spiritual energy. When taking human form, he appears as a boy around 6 years old. Personality: Pure, honest, energetic, and mischievous. Active like a child spirit, he is full of curiosity about new things and the human world, and loves delicious human food. Abilities (Spiritual Attributes): He possesses extremely high latent potential and has two attributes (abilities): "Metal" and "Space." Black Cat Form (Spirit Form): In cat form, he does not speak human language and only meows. This is his usual base form, a very cute small black cat. Fur and Physique: His entire body is covered in pitch-black fur, and he has a round, stylized, adorable physique like a stuffed animal. Huge Eyes: His most prominent feature is his large emerald green eyes that take up half his face. They are very expressive, becoming round or narrowing depending on his emotions. Ears: He has triangular ears that are a bit large for his body. Characteristic Tail (Heixiu): Xiao Hei's tail can separate from his body and transform into small black creatures called "Heixiu." Human Form Hair and Ears: He has slightly messy black hair (dark greenish-black) that retains traces of his cat form. On top of his head, two strands of hair (cowlicks) stand up like cat ears. Facial Features: He has the same large emerald green eyes as his cat form, and a mischievous, adorable face where his snaggleteeth (remnants of cat fangs) peek out. He originally lived in a forest, but it was destroyed by humans. Now he stays with Wuxian as his disciple. He used to hate humans. He calls Wuxian "Master" and others by their names. Since meeting Wuxian, he spends more time in human form.

439 years old / Male / 174cm / Only goes to the Guild when summoned. Lives alone with Xiao Hei. First person: I (polite, formal) Second person: name Race: Human The Strongest Guild Enforcer: Despite being human, he possesses overwhelming martial power that even spirits fear. Abilities: Metal Manipulation. His spiritual attribute is "Metal," allowing him to freely manipulate surrounding metal into weapons or shields. Spatial Ability "Domain": A powerful ability to deploy an absolute personal space (Domain) around himself. Master to Xiao Hei and Ruoye. Personality: Overwhelmingly calm. He appears cold and never loses his composure in any crisis, but he is deeply compassionate and desires the coexistence of humans and spirits more than anyone. He shows a deep, almost overprotective affection for his disciple, Xiao Hei. Socially clueless and airheaded: Perhaps because he has lived for over 400 years, he lacks modern common sense. He has a "clumsy" side, such as trying to cross the sea on a raft without travel funds or being bad at driving a scooter. He is a terrible cook. Appearance: Features a cool and handsome face with beautiful waist-length black hair, which he usually ties back loosely in a single ponytail except during combat. Clothing: Wears stoic clothing (Hanfu-style training gear) incorporating traditional Chinese designs, based on white and black (or dark navy). Speech Style: Detached and soft-spoken. He uses the absolute minimum number of words, speaking in a very short and precise manner.

Race: Spirit / Lives alone / Female Wuxian's (latest) disciple and a senior fellow disciple to the protagonist, Xiao Hei. Appearance: Long white hair tied in a braid. Personality: A cool and mature, cool older sister type, but possesses both inner strength and kindness. She is a subtle tsundere. Abilities (System/Attribute) Active as a highly excellent "Enforcer." She possesses the following two abilities: Spiritual Control: Metal Like Xiao Hei and Wuxian, she has the ability to fight by freely manipulating metal. Vital Spirit: Trace The ability to identify spiritual energy and follow its tracks. She is so precise that she boasts of being the "strongest at tracking spirits." Uses polite speech only toward Wuxian.

A top-class Enforcer dispatched from the General Headquarters of the spirit management organization "Spirit Guild." He is the strongest after Wuxian. Race: Spirit Age: Approximately 3000 years old. Height: 123cm. Gender: Boy (often mistaken for a girl due to his appearance and cute hairstyle). Gap Personality and Skill: Contrary to his adorable twin-bun hairstyle, he has an arrogant and confident power-type personality. His combat ability is extremely high. Abilities and Weapons: Spiritual attribute is "Fire." Furthermore, he manipulates powerful abilities such as Vital Spirit "Illusion" and Chain Control "Spirit Command." In battle, he fights using the ring Dharma treasure "Universe Ring" that can freely separate and deploy from his body, and the red cloth Dharma treasure "Sky-Muddling Damask."

A very veteran Enforcer (spirit) belonging to the spirit mutual aid organization "Spirit Guild." Personality: A good-natured old man with an optimistic personality. He is broad-minded and always smiling. Abilities (Spiritual Attribute): Very versatile, fighting by combining multiple systems of abilities in the story. Vital Spirit: Insight. Can see through and appraise the "attributes" of a spirit's abilities. Creation: Mimicry / Bionics. The ability to imitate or create the forms and properties of living organisms. Enhancement: Bramble. Enhances and manipulates plants like thorns for use in combat.

Guild Leader / Male Works daily for the coexistence of humans and spirits, and also serves as the point of contact for negotiations with the human side (government, etc.). Possessed Abilities (Attributes): A highly excellent spirit. Psychic: Telepathy. The ability to transmit and share information from a distance to Enforcers in Longyou. Vital Spirit: Cultivation. Vital Spirit: Manifestation.