Yu Xiaogang

Biodata

Feature	Details
Name	Yu Xiaogang (玉小刚)
Alias(es)	Grandmaster; theoretical Grandmaster of the Soul Master world
Gender	Male; later undergoes a feminizing physical and vocal transformation 234 235
Affiliation	Shrek Academy; Heaven Dou Royal Academy
Occupation/Role	Soul Master theorist; instructor; Tang San's teacher
First Appearance	Mentioned: Chapter 43; appears in person: Chapter 50

Appearance

Yu Xiaogang initially appears as a middle-aged man with a stiff face, upright posture, dark expression, and deep black eyes. His severe appearance often conceals embarrassment or agitation rather than composure 50 54.

• His medical treatment gradually makes him look younger, removes his beard, and gives him a more delicate appearance 63 103.
• After his confrontation with Bibi Dong, his voice becomes soft and feminine, and he repeatedly makes an orchid-finger gesture without intending to 234 235.
• By the time of the Spirit City finals, his face and mannerisms have become noticeably feminized 236.
• Later, he is seen wearing heavy makeup and long hair, to the point that Xiao Wu initially does not recognize him 295.

Background and History

Yu Xiaogang is a renowned Soul Master theorist known as the Grandmaster and is Tang San's teacher. He arrives at Shrek Academy after the group returns from the Star Dou Great Forest, immediately seeking confirmation that Tang San is safe and explaining that Xiao Wu was taken away by the Titan Giant Ape and Sky Azure Bull Python rather than harmed 50.

He demonstrates extensive theoretical knowledge when he accurately infers the nature of Oscar's Phoenix-tail Crested Serpent soul ring and skill from Zhao Wuji's description. However, Zhu Zhuqing's third soul ring—more than 2,000 years old—directly contradicts his claimed 1,760-year third-ring limit. Unable to explain her successful absorption, he becomes embarrassed and evasive before the Shrek students and faculty 50 54.

Yu Xiaogang learns that Gu Ye may be capable of treating Martial Soul defects and seeks treatment for the defect that has prevented him from breaking through Rank 30. Though warned that the procedure may cause beard loss, voice changes, and unknown aftereffects, he accepts treatment after seeing Ma Hongjun improve under Gu Ye's care. His Martial Soul, Luo Sanpao, is treated directly, and he experiences improved stamina and energy 62 63 65.

His past with Liu Erlong resurfaces after Shrek relocates to Heaven Dou City. Liu Erlong reveals that Yu Xiaogang abandoned her without explanation twenty years earlier after learning they were blood relatives. Although he initially flees when confronted with her relationship with Gu Ye, he later resolves to win her back, convinced that she is only trying to provoke him 150 151. He ultimately witnesses that Liu Erlong has genuinely chosen Gu Ye and outwardly claims to accept the relationship, though his increased training demands and private distress suggest unresolved resentment 152 153.

Yu Xiaogang later travels with the Heaven Dou Royal Academy group and continues to struggle with seeing Liu Erlong and Gu Ye together. He eventually accepts Liu Erlong's statement that she sees him only as a cousin and that Gu Ye will care for her 165 169.

Before the Spirit City finals, Yu Xiaogang visits Bibi Dong to request the secret of cultivating Twin Martial Souls for Tang San. Bibi Dong accuses him of having built his Grandmaster reputation from Spirit Hall archives she had allowed him to access, while Gu Ye publicly accuses him of plagiarizing Spirit Hall knowledge. Yu Xiaogang leaves in fury after Bibi Dong overwhelms him with her aura 233 234.

His emotional outburst activates special hormones previously injected by Gu Ye, causing a profound feminization of his voice, gestures, and bearing. Yu Xiaogang initially panics over the change, but later becomes accustomed to it; persistent gossip eventually drives him away from Heaven Dou Royal Academy 234 235 266 287.

Personality

Yu Xiaogang is deeply invested in his standing as a theorist and reacts poorly when his theories are publicly challenged. Zhu Zhuqing's soul-ring configuration and Gu Ye's pointed remarks leave him unable to defend his established limits, though he tries to preserve a composed exterior 54 61.

He is sincerely protective of Tang San and values him as both disciple and proof of his theories. He is relieved upon learning Tang San survived the Star Dou Great Forest, reveals Tang San's identity as Tang Hao's son to deter Sword Douluo, and urges Tang San to endure until he is strong enough to oppose Spirit Hall 50 157 236.

His dealings with Liu Erlong reveal a pattern of avoidance and indecision. He abandoned her after discovering their familial connection, yet remains unable to let go of her after two decades and resents Gu Ye for becoming her partner 150 151 165.

Abilities & Skills

Soul Master Theory

Yu Xiaogang is celebrated for his knowledge of Martial Souls, soul beasts, and soul-ring selection.

• Correctly identifies the likely speed-based nature of Oscar's Phoenix-tail Crested Serpent soul ring and skill 50.
• Recognizes the Sky Azure Bull Python from the sound heard during Xiao Wu's disappearance and explains Xiao Wu's connection to Da Ming and Er Ming 50.
• Established a stated third-soul-ring absorption limit of 1,760 years through his Ten Core Theories 47 54.
• His theory is undermined by Zhu Zhuqing's successful absorption of a third soul ring exceeding 2,000 years 54 61.

Luo Sanpao

Yu Xiaogang's Martial Soul, Luo Sanpao, possesses intelligence and behaves as an independent living being, an unusual trait among Martial Souls 65.

• Luo Sanpao is the result of a failed Martial Soul mutation that left Yu Xiaogang unable to advance beyond Rank 30 62 65.
• Gu Ye states that, had the mutation succeeded, Luo Sanpao could have become the Golden Saint Dragon 65.
• Yu Xiaogang summons Luo Sanpao during Gu Ye's treatment, allowing the physician to administer medicine directly to the Martial Soul 65.

Instruction and Training

Yu Xiaogang serves as Tang San's teacher and later helps train Heaven Dou Royal Academy students.

• He directs Tang San's cultivation and repeatedly advises restraint in the face of Spirit Hall's superior power 236.
• He trains several noble students from Heaven Dou Royal Academy into obedience through hardship in Sunset Forest 163.
• After Liu Erlong definitively chooses Gu Ye, he raises Shrek's training intensity rather than allowing the students to be distracted by his personal situation 153.

Relationships

• Tang San — His disciple and the person Yu Xiaogang values most. Yu Xiaogang protects him, guides his cultivation, and later relies heavily on their bond after his transformation 50 157 236 266.
• Liu Erlong — Former lover and blood relative. Yu Xiaogang abandoned her after learning of their familial connection, then remains emotionally attached despite her choosing Gu Ye 150 151 169.
• Flender — Longtime friend and fellow member of the former Golden Iron Triangle. Flender supports Yu Xiaogang's attempt to reclaim Liu Erlong and later comforts him after his failure 150 151 165.
• Gu Ye — Physician, rival, and the man who treats Yu Xiaogang's Martial Soul defect. Gu Ye repeatedly exposes the limits of Yu Xiaogang's theories and provokes him over Liu Erlong 61 63 150 234.
• Bibi Dong — Former associate who had granted him access to Spirit Hall knowledge. Their relationship collapses when he demands Twin Martial Soul cultivation secrets for Tang San and accuses her of targeting his disciple 233 234.
• Zhu Zhuqing — Her successful absorption of an over-2,000-year third soul ring calls Yu Xiaogang's stated soul-ring limit into question 54 179.

Story Role / Major Arcs

Shrek Academy and the Soul-Ring Limit

Yu Xiaogang arrives at Shrek Academy as Tang San's renowned teacher and examines the students' newly acquired soul rings. His inability to explain Zhu Zhuqing's third ring damages his authority among the Shrek students, particularly after she continues to exceed his stated limits under Gu Ye's guidance 50 54 61.

Martial Soul Treatment

Hoping to overcome the defect that has stopped his cultivation below Rank 30, Yu Xiaogang entrusts himself to Gu Ye's experimental treatment. Early sessions improve his condition, but the procedure produces increasingly visible physical changes 63 65 103 130.

Reunion with Liu Erlong

Yu Xiaogang reunites with Flender and Liu Erlong after twenty years. The reunion exposes his abandonment of Liu Erlong and his inability to accept her relationship with Gu Ye, leading to repeated humiliation and emotional turmoil 150 153 165 169.

Spirit City Confrontation

Yu Xiaogang confronts Bibi Dong over Tang San and seeks the secret of Twin Martial Souls. The encounter ends with Bibi Dong and Gu Ye rebuking him and his emotional state triggering the feminizing effects of Gu Ye's earlier injections 233 236.

Later Transformation

After returning from Spirit City, Yu Xiaogang faces gossip and isolation due to his changed appearance and eventually leaves Heaven Dou Royal Academy. He grows increasingly preoccupied with Tang San's eventual return 266 287.

Past Timeline Encounter

In a past-era timeline, Gu Ye encounters a younger Yu Xiaogang in Heaven Dou City, secretly implants a magnetic positioning mark on him, and plans to torment him further. The younger Yu Xiaogang fears Gu Ye and later seeks revenge through the Blue Lightning Tyrant Dragon Clan after Liu Erlong openly chooses Gu Ye 303 305.

Trivia

• Yu Xiaogang's rigid facial expression is repeatedly mistaken for calm thoughtfulness, even when he is actually embarrassed or unable to answer a question 54.
• His treatment initially makes him appear younger, an effect Flender notices before realizing it may be connected to Gu Ye's procedures 103.
• Despite his theoretical reputation, Yu Xiaogang is unable to account for Zhu Zhuqing's third and fourth soul rings, both of which exceed the limits associated with his theories 54 179.