Cao Xin

Biodata

Feature	Value
Name	Cao Xin (曹鑫)
Alias(es)	Amorous Douluo; Senior Amorous; Grandpa Cao
Gender	Male
Affiliation	Nine Treasures Glazed Sect
Occupation/Role	Title Douluo; swordsmanship mentor to Lin Yuan
Martial Soul	Affectionate Sword
Status	Active
First Appearance	6

Background / History

Cao Xin is a level 94 Title Douluo of the Nine Treasures Glazed Sect, renowned as the Amorous Douluo. Although he has not traveled the continent for fifty years, his reputation remains formidable; Nan Shuisui describes him as a “Sword Saint” whose prestige is still widely remembered. 6 14

His Affectionate Sword belongs to a family line that also includes the Ruthless Sword martial soul. The two branches separated long ago for unspecified reasons. 6

Cao Xin had no established successor for his sword path before meeting Lin Yuan. Upon seeing Lin Yuan’s Jade Dragon-Slayer martial soul suppress the Affectionate Sword in quality, he eagerly accepted Lin Yuan as his disciple and began teaching him swordsmanship. 6

Personality

Cao Xin is experienced, perceptive, and protective of his disciple, but he is also mischievous and frequently teases Lin Yuan about romance. He openly encourages Lin Yuan’s interest in Ning Tian and later offers similarly suggestive “sword cultivation” advice concerning Lin Yuan’s relationships. 7 15 38

Despite his casual manner, he maintains a clear moral philosophy. He discourages torturing soul beasts merely for a chance at soul bones, arguing that profit should not be the sole measure of one’s actions and connecting this outlook to the Affectionate Sword’s cultivation. 9

He is willing to take calculated risks with Lin Yuan’s cultivation, such as allowing him to test his limits during dangerous soul-ring absorption, but remains ready to intervene if necessary. 9 10 37

Abilities & Skills

Title Douluo Cultivation

Cao Xin is a level 94 Title Douluo, capable of concealing his soul-power fluctuations so completely that Nan Shuisui immediately inferred he had to be a Titled Douluo. 6 12

• Easily incapacitates Tyrannosaurus soul beasts for Lin Yuan and Ning Tian’s soul-ring hunts. 9
• Is able to knock out Xuan Ziwen instantly when Lin Yuan signals him to act. 34
• Keeps soul power prepared to intervene in Lin Yuan and Ji Juechen’s potentially fatal duel. 39

Affectionate Sword

Cao Xin’s martial soul is the Affectionate Sword, a sword path founded on perceiving and incorporating worldly feeling and beauty into one’s blade. 6 7

• Teaches that its ultimate pursuit is to fuse a lifetime of cultivated techniques into one’s bones and blood. 7
• Identifies the path’s key concept as a “state of mind” after Lin Yuan proposes the term. 7
• Recognizes Lin Yuan’s battle-born state of mind—“a single body fighting across three thousand miles; a single sword standing against a million troops”—as an exceptional development of Affectionate Sword intent. 33
• Praises Lin Yuan for bringing the Affectionate Sword to great success within two years. 33

Swordsmanship Instruction

Cao Xin emphasizes fundamentals before techniques, beginning Lin Yuan and Ning Tian’s training with repeated wooden-sword swings. 7

• Guides Lin Yuan in aura refinement and stabilization after breakthroughs. 9 12
• Evaluates Lin Yuan’s combat performance and cautions him against overconfidence. 11
• Offers reflective guidance on sword cultivation after Lin Yuan gains new abilities or reaches pivotal stages. 33 38

Equipment / Items

• Affectionate Sword — Cao Xin’s martial soul and primary weapon. 6 38
• Millennium Whale Glue — Given to Lin Yuan to support his first soul-ring absorption. 6 9
• Storage soul tool — Gifted to Lin Yuan; contains ten cubic meters of storage space. 7
• Gourd of water — Used to support Lin Yuan during sword-training rest periods. 7

Relationships

• Lin Yuan — Disciple. Cao Xin accepts him as his long-awaited successor, trains him in the Affectionate Sword path, evaluates his growth, and follows his orders during their Sun Moon Empire expedition. 6 7 11 34
• Ning Tian — Fellow Nine Treasures Glazed Sect member and student in his sword-training sessions; he frequently teases her about Lin Yuan. 7 9
• Wu Feng — Allows her to join sword training after she declares her wish to protect Ning Tian. 8
• Ning Zhiyuan — Sect Master who involves Cao Xin in Lin Yuan’s recruitment and cultivation arrangements. 6 7
• Nan Shuisui — A fellow senior soul master who recognizes and respects his standing; they negotiate Lin Yuan and Nan Qiuqiu’s sparring wager and the fostering of Nan Qiuqiu. 12 13 15
• Du Busi — Senior associate and fellow mentor figure to Lin Yuan; they observe the younger generation’s cultivation while discussing their potential. 17
• Xuan Ziwen — Cao Xin incapacitates him at Lin Yuan’s signal during the effort to recruit him for the Nine Treasures Glazed Sect. 34 35

Story Role / Major Arcs

Taking Lin Yuan as a Disciple

Cao Xin meets Lin Yuan at the Nine Treasures Glazed Sect, recognizes the extraordinary quality of his Jade Dragon-Slayer martial soul, and accepts him as a disciple to pass on the way of the sword. He gives Lin Yuan Millennium Whale Glue and a storage soul tool. 6 7

Early Sword Training and Soul Hunting

He trains Lin Yuan, Ning Tian, and later Wu Feng in sword fundamentals and explains the emotional philosophy behind the Affectionate Sword. He then escorts Lin Yuan and Ning Tian into the Star Dou Great Forest, captures suitable Tyrannosaurus soul beasts, and supervises their soul-ring absorption. 7 8 9

Cao Xin proposes using Whale Glue to help Lin Yuan risk absorbing a near-millennium first soul ring. After Lin Yuan succeeds, Cao Xin assesses his new Will of the Dragon skill and concludes that he can reliably defeat most Spirit Elders below level 32. 9 11

Earth Dragon Sect Encounter

When Nan Qiuqiu challenges the group over the Tyrannosaurus soul beasts, Cao Xin arranges a spar between her and Lin Yuan. He later coordinates with Nan Shuisui to find a Rouge Python so Nan Qiuqiu can obtain her first soul ring, supporting closer ties between the Earth Dragon Sect and Nine Treasures Glazed Sect. 12 13 15

Sun Moon Empire Expedition

Two years later, Cao Xin accompanies Lin Yuan through the Sun Moon Empire. He witnesses Lin Yuan repel a twenty-thousand-year Red Iron Earth Dragon with a sword strike and recognizes the immense state of mind embedded in that attack. 33

He assists Lin Yuan’s recruitment of Xuan Ziwen by knocking the soul engineer unconscious, then continues accompanying Lin Yuan during the search for powerful dragon-type soul rings. 34 36 37

Sword Duel with Ji Juechen

Cao Xin observes Lin Yuan’s deadly duel with Ji Juechen and prevents Jing Ziyan from interrupting prematurely, trusting that the two swordsmen will not completely lose their senses. When they prepare to resolve the fight with one final strike, he readies himself to save them if needed. 39

Notable Quotes

“You must first use your heart to feel all the emotions and beauty in this world.” 7

“If you get a Soul Bone, it is your good fortune; if you don't, it is your fate. Why torture a life for something that might not be destined for you?” 9

“The road ahead will be magnificent.” 11

Trivia

• Cao Xin is older in appearance than Du Busi but is actually twenty to thirty years younger. 17
• He has no descendants, a fact other Title Douluos tease him about when discussing succession. 6
• Lin Yuan privately identifies him as a lecherous old man beneath a solemn exterior. 7
• Cao Xin commonly calls Lin Yuan “Little Yuan” or “Xiao Yuan.” 9 12