Chapter Summaries

Muzan forced Xiang Kai to absorb large amounts of his blood to evolve his spatial Blood Demon Art, then named the expanded ability Infinity Castle. Xiang Kai survived but became muddled, and Muzan kept him around as a temporary substitute for Nakime.

• Xiang Kai mistook Muzan’s promise of a reward for an offer to make him an Upper Rank, but Muzan injected him with blood to strengthen his Blood Demon Art instead.
• Xiang Kai’s first evolution let him move rooms and their occupants together, but Muzan dismissed the ability as too limited and injected him with more blood.
• Xiang Kai’s second evolution expanded Drum House’s reach across several hundred meters, though the changes became imprecise and often misplaced objects.
• Muzan told Xiang Kai to stay with him for now and renamed his Blood Demon Art Infinity Castle, then accepted Xiang Kai’s praise of the name.

Yan Zi delivered blood samples from Upper Rank Two and Upper Rank Four to Tamayo, while the Hashira gathered at the Ubuyashiki Mansion to hear news of Xia Xi and Tanjuro’s achievements. Kagaya Ubuyashiki announced that Tanjuro Kamado would join the Nine Hashira as the Sun Hashira.

• Yan Zi told Tamayo that Tanjuro had killed a demon suspected to be a Crescent Moon and escaped Upper Rank Four, while Xia Xi had defeated Upper Rank Two.
• Yan Zi delivered blood samples from Upper Rank Two and Upper Rank Four, and Tamayo eagerly considered how they could advance her research.
• The Hashira gathered with Tanjuro at the Ubuyashiki Mansion, where Gyomei and Kazetoriin noticed the closeness between Xia Xi and Kanae.
• Kagaya Ubuyashiki announced Tanjuro’s achievements and named him the new Sun Hashira.

Tanjuro formally became the Sun Hashira and briefed the Hashira on the Upper Rank demons and their abilities. Xia Xi considered the Corps’ strengthened fighters and wondered whether Muzan’s unknown strength could exceed Challenge Level 100.

• Ubuyashiki welcomed Tanjuro as a Hashira, and Tanjuro pledged to honor the trust placed in him.
• Tanjuro described Nakime’s spatial Blood Demon Art and estimated that Pot Monster was dangerous but weaker than the previous Upper Rank Four.
• The Hashira reviewed the demons’ strength and their own gains from War Marks and Supreme Territories.
• Xia Xi assessed the Corps’ growing power but remained uncertain how strong Muzan was.

After Ubuyashiki ordered Xia Xi and Tanjuro to hide at Tamayo’s research institute for their safety, Xia Xi pondered how he could reach Yoriichi’s level and went there with Kanae to discuss his ideas. The Hashira held ranking matches without War Marks while Xia Xi was away, and Tanjuro narrowly lost to Shinjuro Rengoku.

• Ubuyashiki ordered Xia Xi and Tanjuro to protect Tamayo and keep a low profile at the research institute while the Corps improved its counter-surveillance.
• Tanjuro accepted the assignment, and Xia Xi agreed, hoping to train and discuss Yoriichi’s strength with Tamayo.
• Xia Xi left the meeting with Kanae before the ranking matches, while the other Hashira required Tanjuro to compete without using War Marks.
• Tanjuro defeated Kazetoriin but narrowly lost to Big Owl, while Uzui defeated Shinjuro Rengoku before losing to Gyomei.
• The following day, Xia Xi arrived at Tamayo’s research institute supporting Kanae, whose legs were weak.

Xia Xi asked Tamayo to estimate his chances against Muzan, and she judged them below ten percent even with his planned boosts. He accepted the warning and began considering ways to grow stronger, including special training and several ideas of his own.

• Tamayo welcomed Xia Xi and Kanae, noticed their growing intimacy, and thanked Xia Xi for bringing her valuable Upper Rank blood samples.
• Xia Xi described Upper Rank Two as unimpressive, while Kanae explained that the demon was powerful and that Xia Xi had simply outmatched him.
• Xia Xi asked Tamayo how he would fare against Muzan with his Supreme Territories, [War Mark], and further training.
• Tamayo said Xia Xi would have less than a ten percent chance against Muzan at his peak, though she admitted her fear of Muzan might make her assessment pessimistic.
• Xia Xi decided he needed intensive training and began considering ways to become strong enough to face Muzan, including three ideas he had already devised.

Xia Xi considered three ways to grow strong enough to catch up to Yoriichi Tsugikuni: develop his Breathing Styles and attributes, expand his skill deck, and seek a breakthrough beyond the three forms of Supreme Territory. Tamayo could not suggest a way to train for the hypothesized Ultimate Transcendence, so Xia Xi planned to keep practicing and rely on further growth and the System for guidance.

• Xia Xi estimated that raising Dawn Breathing and the other Basic Breathing Styles could greatly increase his attributes, though it would take years of training.
• Xia Xi considered training Constant across the Basic Breathing Styles to unlock a higher-level skill like True Constant.
• Xia Xi proposed combining the Supreme Territories of Body, Technique, and Mind into an Ultimate Transcendence that might explain Yoriichi Tsugikuni’s immense power.
• Tamayo and Kanae were stunned by Xia Xi’s ideas, and Kanae resolved to grow stronger so she could stand beside him.
• Tamayo asked how they could train for Ultimate Transcendence, and Xia Xi suggested fantastical training methods before deciding to keep practicing the three Supreme Territories and raise Dawn Breathing further.

Xia Xi intensified his training while improving several skills, and Kanae told him she would leave the research institute for a mission. They discussed their hopes for life after defeating the Demons and renewed their promise to win, then spent the night together before her departure.

• Xia Xi trained with all three domains active, gaining Dawn Breathing proficiency and improving his stats and Life Skills.
• Kanae accompanied Xia Xi in training, while Yushiro overheard their suggestive remarks and Tamayo remained absorbed in research.
• Kanae told Xia Xi she would leave the research institute on a mission and asked what he wanted to do after Muzan and the Demons were defeated.
• Xia Xi said he might seek powerful opponents abroad, while Kanae hoped to live as a family, treat people, and watch Shinobu, Ye Ying, and their future children grow.
• Xia Xi promised Kanae they would defeat all the Demons, and the two spent the night together as Yushiro and Tanjuro struggled to sleep.

Xia Xi spent Achievement Points to raise Dawn Breathing to level 8 and Flame Breathing to level 4, greatly increasing his abilities and stats. As he wondered what remained to unlock the territory-fusion effect he sought, Tanjuro arrived to tell him that Miss Persimmon had come to see him.

• Xia Xi sparred regularly with Tanjuro while Kanae was away, and both men grew stronger through their training.
• After his Achievement Points reached 37, Xia Xi went to a deserted hill and spent points upgrading Dawn Breathing and Flame Breathing.
• The upgrades raised Xia Xi’s Energy Level to 1364 and strengthened his Transparent World, Bright Red Nichirin Blade, and attacks.
• Xia Xi tested his abilities and concluded that he had become one of the strongest people of the current era, though he still had not unlocked the territory-fusion effect.
• Tanjuro found Xia Xi on the hill and told him that Miss Persimmon had come to see him.

Xia Xi returned to the research institute after an astonishing training session and found Persimmon distressed. Persimmon confronted him about being with Kanae and told him she had known him first, leaving Xia Xi bewildered as she struggled to voice her hurt.

• Tanjuro noticed how dramatically Xia Xi's body had changed and asked what training he had done; Xia Xi bragged about his talent and microscopic control of his body.
• Tamayo served Persimmon tea and realized she had come because she was upset about Xia Xi and Kanae.
• Xia Xi arrived with Tanjuro, and Tamayo and Tanjuro left the room so he and Persimmon could talk privately.
• Persimmon asked Xia Xi whether he was with Kanae and protested that she and Xia Xi had known each other before Kanae did.
• Persimmon recalled their shared history, clutched the white jade magatama, and tearfully said she had been there first.

Persimmon confronted Xia Xi over choosing Kanae as his first romantic partner, and Xia Xi said he was holding back because Persimmon was still a minor. Persimmon accepted eighteen as the deadline for him to reconsider, then stormed off, leaving Xia Xi unsure whether he should follow her.

• Persimmon told Xia Xi she had changed her clothes and stayed at the Dojo to suit his preferences, then asked why he had not chosen her first.
• Xia Xi checked his system and found that a cognitive filter related to Persimmon being a minor could be shaping his feelings.
• Xia Xi told Persimmon he cared about her but wanted to wait until she turned eighteen before discussing romance.
• Persimmon set eighteen as the deadline and left in a huff while Tamayo, Yushiro, and Tanjuro listened outside.
• Tanjuro asked Xia Xi whether he was going after Persimmon, and Xia Xi wondered why he should.

Xia Xi chased after Persimmon and eased her anger by taking her shopping and to a movie. In the days that followed, the laboratory became a regular gathering place for Xia Xi’s visitors and training partners, while his combat strength proved far beyond the other Hashira’s.

• Xia Xi hurried after Persimmon, then returned hours later after taking her shopping and to a movie; Tanjuro learned she seemed less angry.
• Kanae, Persimmon, and Shinobu Kocho began visiting Xia Xi at Tamayo’s laboratory, each arriving separately.
• Tanjuro used the girls’ visits as a chance to return home, trusting the powerful Hashira gathered at the laboratory to protect it.
• Hashira and provisional Hashira began coming to spar with Xia Xi in groups, but even several marked fighters could not make him use his full strength.
• Xia Xi’s immense physical attributes and stacked enhancements gave him combat strength that left even Gyomei awestruck.

Xia Xi’s overwhelming strength and the Demon Slayer Corps’ growing power were tested as the Twelve Kizuki became more aggressive. After Kiseki Tokito defeated Lower One Rokuro, he filled the final vacancy among the Nine Hashira as the Moon Hashira.

• Xia Xi’s War Mark let him crush Gyomei, Tengen Uzui, and Shinjuro Rengoku in sparring, even after Tanjuro joined their side.
• The Hashira and Provisional Hashira grew stronger through rotating sparring sessions, and Xia Xi gave Murata private instruction until Murata reached standard Hashira strength.
• The Twelve Kizuki began moving between cities and targeting Demon Slayer Corps members, though most attacks failed to find strong swordsmen.
• Kiseki Tokito defeated the new Lower One, Rokuro, with his refined Moon Breathing.
• Kiseki Tokito filled the last vacancy among the Nine Hashira and became the Moon Hashira.

Xia Xi sparred with Sabito, Giyu, and Makomo, easily turning aside their coordinated attacks until he told them to activate their war marks. The three gained strength and speed, and Xia Xi advanced toward them as they prepared to fight again.

• Xia Xi reflected on Kiseki Tokito's promotion to Hashira and the relative strengths of the Demon Slayers, including Kazetoriin's progress toward Transparent World.
• Sabito, Giyu, and Makomo challenged Xia Xi to spar at the reinforced training ground behind the research institute.
• The trio coordinated attacks using their Waterfall, Water, and Rain Breathing styles, but Xia Xi dodged or blocked them and repeatedly knocked them into the mud.
• Sabito urged Giyu and Makomo to continue fighting, and they renewed their combined assault, but Xia Xi brought Makomo down again.
• Xia Xi told the three to activate their war marks, and their marks appeared as their swords began to glow.
• Xia Xi started toward the marked trio as they faced him with resolve.

Xia Xi found and gathered Blue Spider Lily samples at Yoriichi and his wife’s graves, but the flowers withered almost immediately. Tamayo examined the samples and warned that the rare flowers might be nearing extinction, leaving their fate uncertain as research began.

• Xia Xi continued training the Demon Slayer Corps, while his puppet fighters and Tamayo’s drugs strengthened the organization.
• Xia Xi returned to Tanjuro’s old home and found Blue Spider Lilies blooming beside Yoriichi and his wife’s graves.
• Xia Xi gathered several flowers, but the remaining blooms and his samples rapidly withered; the System identified the plant as a World-Class Special Item affected by source consciousness.
• Xia Xi brought the samples to Tamayo’s institute, where Tamayo, Yushiro, and Tanjuro examined the shriveled, yellow-brown specimens.
• Tamayo reasoned that the flowers’ brief, sunlight-dependent bloom made them inaccessible to Muzan and suggested they might naturally go extinct; she began researching the samples.

After a week of testing, Tamayo and Xia Xi found no special effects in the Blue Spider Lily and developed two theories for why it had failed to reproduce Muzan’s transformation. The Demon Slayer Corps then identified more than a dozen possible Muzan Kibutsuji suspects and sent Xia Xi to investigate, ordering him to retreat immediately if he confirmed Muzan’s identity.

• Tamayo, Yushiro, Kanae, Shinobu, and Xia Xi spent a week testing Blue Spider Lily samples, but none of their experiments produced unusual effects.
• Tamayo and the others proposed that Muzan’s transformation had depended on the ancient doctor’s and Muzan’s unusual circumstances, or that the medicine had only worked for someone with Muzan’s illness.
• Xia Xi and the others agreed that Muzan Kibutsuji must never obtain the Blue Spider Lily, even if the chance of it empowering him was small.
• The Intelligence Department gave Ubuyashiki a list of more than a dozen suspects matching Muzan’s known characteristics, and he ordered the agents to stay back while Ninja Beasts monitored them.
• Ubuyashiki assigned Xia Xi to investigate the suspects with support from the other Hashira and ordered him to withdraw as soon as he confirmed Muzan’s identity.
• Ubuyashiki secretly ordered several Hashira to protect Xia Xi and help him escape if Muzan discovered the reconnaissance operation, and none of them objected.

Xia Xi investigated suspects across Japan using the System’s energy readings, finding mostly ordinary people and a few hidden demons. In Tokyo, he identified the wealthy man’s daughter Jialuo as the Demon King after seeing her energy level of 61,491.

• Xia Xi traveled to Kyoto and ruled out a medicine merchant as Muzan after reading his energy level as 11.
• Xia Xi and Gyomei Himejima investigated a foreign merchant in Osaka, discovered he was a cultist rather than a demon, and turned him over to the police.
• Xia Xi searched suspects in Yokohama, Fukuoka, Tokyo, and other cities, quietly killing hidden demons he encountered to gain experience.
• Xia Xi observed Jialuo during a staged meeting and signaled to Shinjuro that she was the Demon King.
• Xia Xi saw Jialuo’s energy level of 61,491 and realized he had initially mistaken the number by a digit.

Xia Xi discovered that Muzan Kibutsuji’s strength was overwhelming, despite lasting wounds left by Yoriichi, and warned the Demon Slayer Corps that they could not defeat him in a direct fight. The Corps favored an immediate decisive battle, but Ubuyashiki urged them to wait for Tamayo’s anti-Muzan drug while considering the danger of Muzan escaping or hiding.

• Xia Xi examined Muzan Kibutsuji’s stats, found his energy level exceeded sixty thousand, and identified lingering debuffs from wounds inflicted by Yoriichi.
• Xia Xi and Shinjuro withdrew while a covert operative near Muzan received instructions to leave without raising suspicion; Muzan sensed nearby Hashira but did not pursue them.
• Xia Xi told Shinjuro that Muzan could kill them nine times in a minute and that the Demon Slayer Corps had no one capable of matching him head-on.
• The Demon Slayer Corps held an emergency meeting after Muzan’s reappearance, and the Hashira and Ubuyashiki favored launching a decisive battle soon.
• Ubuyashiki warned Xia Xi that Muzan might flee overseas or hide in another space, but said they should wait for Tamayo’s drug to prevent Muzan from splitting and poison his body.

Tamayo worked to develop drugs against Muzan while Xia Xi and the Demon Slayer Corps prepared a strategy for the final battle. As his training gains stalled, Persimmon stayed near the research institute to help him train, and the Corps awaited the last piece needed to begin the confrontation.

• Xia Xi reasoned that Tamayo’s drugs, intelligence, and antidote would need to weaken Muzan substantially and make her a leading candidate for MVP.
• Xia Xi, the Nine Hashira, and Ubuyashiki coordinated plans to lure Muzan out, control the timing and location of the battle, and keep the Twelve Kizuki from joining him.
• Xia Xi raised all five major basic Breathing Styles to level 5, bringing his energy level to 1485 and upgrading [Constant] to [True Constant].
• Xia Xi remained unable to unlock Junior College Domain: Ultimate Transcendence and worried that the Corps lacked enough strength for the final battle.
• Persimmon entrusted Northern Region affairs to Kazami and other core swordsmen, then stayed near the research institute to spar with Xia Xi and support his training.

Xia Xi realized Persimmon had prepared a numbing soup to leave him unable to resist her, after she decided to take the romantic initiative herself. The chapter ended with Persimmon locking the room until morning while Xia Xi remained unable to speak or move.

• Xia Xi paused his meditation to drink soup Persimmon had made, unaware that she had secretly added a drug.
• Persimmon reminded Xia Xi that he had forgotten something he had promised her, and he recalled her romantic feelings for him.
• Xia Xi tried to tell Persim he was willing to respond to her feelings, but the soup left him unable to control his body or speak.
• Persimson revealed she had asked Tamayo for a formula designed to incapacitate Xia Xi and explained that she intended to claim what she wanted.
• Persimmon closed and locked the door, assuring Xia Xi that no one would disturb them until morning.

Persimmon secretly drugged Xia Xi and used the opportunity to train with him, but their encounter turned into a nightlong struggle before he regained his strength. The next morning, Xia Xi urged Tamayo to finish her medicine so they could kill Muzan Kibutsuji, and she said it was nearly ready.

• Tamayo realized Persimmon had taken the drugged soup to Xia Xi and decided not to interfere.
• Persimmon began training with the incapacitated Xia Xi, and her Snow Breathing and War Mark activated as she grew more skilled.
• Xia Xi recovered from the anesthetic earlier than expected and overpowered Persimmon in turn.
• The following morning, Tamayo teased Xia Xi about his tired appearance, and he urged her to hurry the medicine so they could kill Muzan Kibutsuji.
• Tamayo said her medicine was nearly ready.