Chapter Summaries

Mu Yu left the Butterfly Mansion and headed for Mt. Sagiri to learn the Dance of the Fire God, while reviewing his strengthened abilities and accumulated lottery draws. He used one draw to obtain a Night Set that only made him more handsome.

• Mu Yu said farewell to Shinobu Kocho, who looked forward to the day his Nichirin Blade received its true name.
• Mu Yu set out for Mt. Sagiri, determined to learn the Dance of the Fire God and create his own Breathing Technique.
• Mu Yu asked the system to distribute his Energy Droplets and display his stats, revealing major increases in his physique and Haki and three lottery draws.
• The system told Mu Yu that his physique let him activate Markings whenever he wished, but he chose to wait until he learned the Dance of the Fire God.
• At noon, Mu Yu used a lottery draw and received a Night Set whose only effect was making him more handsome.

Mu Yu obtained a stylish Night Set and a mini-map that revealed demons across the city, then began hunting them with a route planned by the system. When Demon Slayer Corps members faced a deadly Twelve Kizuki at Komine Castle, Mu Yu arrived just as its giant discs were about to crush them.

• Mu Yu admired the Night Set’s appearance and learned it stayed clean and restored itself after damage.
• Mu Yu drew a mini-map that showed allies and enemies within a city, including numerous demons.
• Mu Yu asked the system to plan an efficient route and spent half a day killing demons across nearly half the city.
• At Komine Castle, wounded Demon Slayer Corps members struggled against a Twelve Kizuki whose changing attacks had killed several of their companions.
• As giant spinning discs closed in on the survivors, Mu Yu rushed in and cleaved both discs in half.

Mu Yu killed Lower Rank Two, Wheel, with a single strike and taught the wounded Demon Slayer Corps members to control their breathing and close their wounds. Murata returned unharmed after escaping a rolling millstone by falling into an abandoned trap.

• Wheel recognized Mu Yu as someone the Twelve Kizuki were permitted to flee from, but he could not move as Mu Yu cut off his head.
• Mu Yu guided the injured Demon Slayer Corps members through breathing exercises until they controlled their bleeding wounds.
• Mu Yu urged the Demon Slayer Corps members to keep practicing True Total Concentration and precise control of their blood vessels.
• Murata returned unharmed and explained that a rolling millstone had become trapped after he fell into an abandoned trap.

Mu Yu encouraged Murata after rescuing the Demon Slayer Corps members, then continued hunting demons through the night. At Mt. Sagiri, Tanjiro reunited with Mu Yu and learned that Mu Yu had influenced Urokodaki’s training methods.

• Mu Yu reassured Murata, praised his potential, and left him to care for the wounded.
• Mu Yu hunted demons attacking people, and those he rescued glimpsed his cloaked figure.
• Tanjiro returned to Urokodaki’s cabin after failing to cut the boulder and worrying about Nezuko’s long sleep.
• Tanjiro sensed Mu Yu’s powerful presence and learned he was the lord who had helped Nezuko gain the Demon Slayer Corps’ acceptance.
• Urokodaki told Tanjiro that Mu Yu’s plan had shaped his training methods, leaving Tanjiro shocked.

Mu Yu told Tanjiro and Sakonji Urokodaki that the Kamado family’s Dance of the Fire God came from Tsugikuni Yoriichi’s Sun Breathing, then recounted Yoriichi’s childhood and his brother Kokushibo’s growing jealousy. The story left Kokushibo consumed by envy of Yoriichi’s extraordinary talent.

• Tanjiro felt grateful for Mu Yu’s help, and Mu Yu asked him to teach the Dance of the Fire God.
• Mu Yu revealed that the dance was the first twelve forms of Sun Breathing, passed down from Tsugikuni Yoriichi, and explained the origins of Tanjiro’s Sun Earrings.
• Mu Yu recounted how Yoriichi’s father planned to send him to a temple, while his mother protected him and Kokushibo secretly befriended him.
• At age seven, Yoriichi spoke for the first time, then defeated a grown swordsman with ease during his first fight.
• Yoriichi explained that he could see inside people’s bodies and predict their movements, leaving Kokushibo jealous of his brother’s talent and uninterestedness in swordsmanship.

The chapter recounted Yoriichi’s life, from leaving home and finding a family with Uta to losing her and their child to demons, then becoming a Demon Slayer and nearly killing Muzan. After Muzan escaped and Kokushibo became a demon, Yoriichi was expelled from the Corps and lived with regret, finding his last warmth with Sumiyoshi’s family.

• After their father chose Yoriichi for the priesthood instead of Kokushibo, Yoriichi left home, and Kokushibo grew to resent him.
• Yoriichi met Uta, went home with her, and married her ten years later.
• While Yoriichi was away seeking a midwife, demons murdered Uta and their unborn child.
• Guided by the Flame Hashira, Yoriichi joined the Demon Slayer Corps, created Sun Breathing, and taught the other foundational Breathing Techniques.
• Yoriichi nearly killed Muzan, but Muzan escaped; Tamayo broke free of his control and offered to help Yoriichi.
• Yoriichi learned that Kokushibo had become a demon, was expelled from the Corps, and later received comfort from Sumiyoshi’s family.

Mu Yu recounted how Yoriichi entrusted the Kamado family with the Sun Earrings and Sun Breathing sword kata, which became the Dance of the Fire God. Tanjiro taught Mu Yu the dance and its breathing techniques, and Mu Yu mastered Sun Breathing, gaining major rewards and raising his Swordsmanship Tree to level 25.

• Yoriichi confided his tragic past to Sumiyoshi, and Sumiyoshi’s young son comforted him with a smile.
• Yoriichi demonstrated Sun Breathing for Sumiko and Sumiyoshi, then left the Sun Earrings and sword kata with Sumiyoshi to pass down.
• Sumiyoshi called after Yoriichi, insisting he was not a worthless failure, and promised to preserve the earrings and kata.
• Mu Yu told Tanjiro and Sakonji Urokodaki about Yoriichi’s history, including his attack on Muzan and the origin of the Dance of the Fire God.
• Tanjiro agreed to teach Mu Yu the Kagura Dance, performed its forms, and taught him their corresponding breathing techniques.
• Mu Yu mastered Sun Breathing and its sword kata, earning 150 million Energy Points as his Swordsmanship Tree rose from level 23 to level 25.

Mu Yu demonstrated Sun Breathing by performing the Kagura Dance for nine days and nine nights, leaving Tanjiro and Sakonji Urokodaki astonished. Tanjiro began to understand his father’s connection to the dance, while Mu Yu’s aura transformed before he finally stopped.

• Mu Yu used Sun Breathing to perform the Kagura Dance, and Tanjiro recognized how little he had understood the dance his father had taught him.
• Mu Yu linked Sun Breathing forms together and continued dancing for an entire day while Tanjiro and Sakonji Urokodaki watched and tried to learn.
• Tanjiro managed one move with Sun Breathing before nearly exhausting himself, while Sakonji Urokodaki could not use the technique.
• Mu Yu continued practicing over the following days, developing a leaf-shaped mark on his cheek and an aura that reminded Tanjiro of his father.
• Mu Yu danced for eight days and nights without stopping, and Tanjiro worried as his presence became increasingly difficult to sense.
• Mu Yu finally stopped after nine days and nine nights, leaving Tanjiro and Sakonji Urokodaki in awe.

After mastering Sun Breathing and the Transparent World, Mu Yu helped Tanjiro overcome his training obstacles with three tailored methods. As Mu Yu prepared to leave Mt. Sagiri, Tanjiro asked how to turn Nezuko human, and Mu Yu said there was a way.

• After nine days and nights of practicing Sun Breathing, Mu Yu felt renewed and discovered that his senses and bodily control had greatly improved.
• Mu Yu ate a hearty meal, then identified Tanjiro's weaknesses in breathing and swordsmanship and offered him three ways to improve.
• Mu Yu corrected Tanjiro's Water Breathing, taught him to sharpen his sense of smell, and implanted a Haki Seed to help him develop Haki.
• Tanjiro benefited from Mu Yu's guidance and the Sun Breathing demonstration, while his sensitive nose detected Mu Yu's sorrow at parting.
• Tanjiro asked Mu Yu how to turn Nezuko back into a human, and Mu Yu told him there was a way.

Mu Yu offered Tanjiro a choice between having Nezuko become human or letting her use the Blue Spider Lily to overcome sunlight, but Nezuko rejected the flower and chose to embrace her brother. Tanjiro decided to seek a cure that would let Nezuko become human, and Mu Yu was left wishing he had a little sister.

• Mu Yu told Tanjiro about Tamayo, a doctor who could research a way to turn Nezuko human, and revealed the Blue Spider Lily as another possibility.
• Mu Yu showed Tanjiro the Blue Spider Lily, and Tanjiro admitted he could not choose for Nezuko.
• Mu Yu brought Tanjiro to Nezuko, who woke when she smelled the flower.
• Nezuko reached for the Blue Spider Lily but pushed it back, then hugged Tanjiro and patted Mu Yu's head.
• Tanjiro thanked Mu Yu and said he wanted Nezuko to become human so they could live and grow old together.

After the world line began to converge, Mu Yu spent six months sweeping demons across Japan, driving Muzan Kibutsuji into hiding in Infinity Castle. When two demons finally appeared on his map, Upper Rank One Kokushibo confronted him, claiming he would not lose again.

• The system warned Mu Yu that Muzan Kibutsuji would learn of the Blue Spider Lily and that the world line had begun to converge.
• Mu Yu used the little map to hunt demons across Japan, while Muzan changed the demons’ rules and hid in Infinity Castle.
• After six months, Mu Yu had nearly cleared Japan of demons but could no longer locate Muzan or the Twelve Kizuki.
• The Demon Slayer Corps strengthened its forces and prepared to welcome Muzan at headquarters as Mu Yu continued his patrols.
• Mu Yu’s map revealed two demons, and Kokushibo appeared before him while the other demon remained concealed.
• Kokushibo said he had volunteered to fight Mu Yu and would never lose again, and Mu Yu answered with a smile.

Mu Yu confronted Kokushibo and overwhelmed the Upper Rank One with his swordsmanship and Sun Breathing. As Kokushibo struggled to understand why another human like Yoriichi stood beyond him, he asked Mu Yu whether he had ever been jealous of anyone.

• Kokushibo sensed Mu Yu's unusual physique but could not see through his body with the Transparent World.
• Mu Yu recognized Kokushibo's two brains and three hearts and learned that Kokushibo still remembered Yoriichi.
• Kokushibo attacked with Moon Breathing, but Mu Yu broke his sword and cut open his chest with one strike.
• Kokushibo regenerated and unleashed several powerful Moon Breathing forms, while Mu Yu's Sun Breathing burned through the attacks and wounded him.
• Kokushibo questioned why Mu Yu and Yoriichi were so different from other humans and asked whether Mu Yu had ever been jealous of anyone.

Mu Yu fought Kokushibo as Kokushibo’s jealousy and memories of Yoriichi drove him to unleash his strongest techniques. After Mu Yu severed Kokushibo’s head and arms, Kokushibo transformed himself and launched a final attack that collided with Mu Yu’s Sun Breathing.

• Kokushibo challenged Mu Yu over whether someone as gifted as him could understand jealousy, and Mu Yu admitted envying people who were more eloquent and popular.
• Mu Yu countered Kokushibo’s Moon Breathing with Sun Breathing, swallowing the moon blades in a Black Domain and leaving Kokushibo disheveled.
• Kokushibo recalled Yoriichi’s final encounter with him, when Yoriichi nearly killed him before dying peacefully, leaving Kokushibo haunted by humiliation for more than four hundred years.
• Kokushibo unleashed his peak technique, but Mu Yu severed his head and hands in one strike.
• Kokushibo regenerated into a grotesque form covered in blades and eyes, then used Moon Breathing’s Seventeenth Form as Mu Yu met it with Sun Breathing’s Thirteenth Form.

Mu Yu defeated Kokushibo with the thirteenth form of Sun Breathing, and Kokushibo died while confronting his lifelong envy of Yoriichi. His final realization was that he had always wanted to become his younger twin brother.

• Mu Yu's Cycle of Fate overwhelmed Kokushibo's strongest technique and severed the organs hidden in his body.
• Kokushibo accused Mu Yu and Yoriichi of being favored by heaven, while Mu Yu dismissed his jealousy.
• Kokushibo's cells continued to burn from Mu Yu's sword aura, and he failed to regenerate despite his desperate resistance.
• As he died, Kokushibo remembered the life he had envied Yoriichi and realized he had wanted to become him.
• Kokushibo turned to ash, leaving behind the flute he had cut in two centuries earlier.

Mu Yu lured Muzan Kibutsuji into bringing him to Infinity Castle by threatening to destroy the Blue Spider Lily. He overwhelmed the demons with gravity and struck Nakime down, leaving her unable to control her hands as Muzan demanded she expel him.

• Mu Yu taunted Muzan Kibutsuji with the Blue Spider Lily and began counting down, forcing Muzan to order Nakime to bring him into Infinity Castle.
• Mu Yu used Geppo to stop his fall, then found himself surrounded by demons as Muzan and the Twelve Kizuki watched from above.
• Mu Yu increased the gravity throughout Infinity Castle, crushing the demons and forcing the Twelve Kizuki to their knees while Muzan anchored himself with tentacles.
• Mu Yu struck Nakime with Great Star Shock, splitting her in half and preventing her from regenerating.
• Muzan ordered Nakime to expel Mu Yu, but Nakime could not control her trembling hands well enough to use her biwa.

Mu Yu attacked Muzan Kibutsuji and the demons gathered in the Infinity Castle after disabling Nakime and removing his gravity control. He slaughtered the demon fodder and several Upper Ranks, leaving the remaining demons stunned and terrified.

• Muzan Kibutsuji ordered the demons to attack Mu Yu after the gravity pressing them down vanished.
• Mu Yu rushed the beast-shaped demon soldiers and swiftly cut them to pieces, freeing the humans Muzan had transformed.
• Gyokko, Gyutaro, Daki, and Hantengu attacked Mu Yu with their Blood Demon Arts.
• Mu Yu beheaded Gyokko and cut apart the other demons’ attacks, leaving several Upper Ranks in fragments.
• Kaigaku, newly promoted to Upper Rank Six, watched in horror as Mu Yu overwhelmed the demons.

Mu Yu overwhelmed the demons in the Infinity Castle, killing Gyokko and the other demons while Muzan Kibutsuji avoided fighting him. Muzan took control of the castle through Nakime and escaped Mu Yu’s attack, leaving the two enemies separated as Muzan resolved to outlive him.

• Muzan Kibutsuji ordered the demons to attack Mu Yu, but Mu Yu killed Gyokko after evading his Blood Prison Pot.
• Daki, Gyutaro, Hantengu, Kaigaku, and the other demons launched a desperate assault, but Mu Yu held them off and killed them with Sun Breathing.
• Muzan Kibutsuji pierced Nakime with his tentacles and used her body to take control of the Infinity Castle.
• Mu Yu attacked Muzan, but Muzan moved himself and Nakime a hundred meters away by manipulating the castle.
• Muzan refused to risk fighting Mu Yu and decided to survive until Mu Yu died of old age.

Mu Yu forced Muzan Kibutsuji out of Infinity Castle by manipulating gravity and buoyancy, destroying the demon’s refuge. Muzan emerged in his strongest form, but Mu Yu’s sword strike and arrival left him terrified.

• Mu Yu challenged Muzan Kibutsuji, then used Hell Journey to increase gravity, but Nakime’s control of Infinity Castle let Muzan evade him.
• Mu Yu used Zero-Gravity Control to lift and demolish Infinity Castle while Muzan struggled to maintain control through Nakime.
• Muzan pushed Nakime beyond her limits, causing her body to collapse, then escaped as Infinity Castle crumbled.
• Muzan emerged from the ground in his strongest form and prepared to ambush Mu Yu as he escaped through an opening.
• Mu Yu cleaved a huge fissure in the ground with one sword strike and appeared before Muzan, who felt more terrified than he had when facing Yoriichi.

Mu Yu fought Muzan Kibutsuji, cutting apart his opening attack and then pressing him with speed, swordsmanship, and gravity. The chapter left Muzan screaming in agony as Mu Yu’s flames burned through his body.

• Muzan Kibutsuji launched a massive tentacle ambush, but Mu Yu severed the tentacles with his swords.
• Mu Yu and Muzan Kibutsuji assessed each other and chose opposite strategies: Mu Yu aimed to end the fight quickly, while Muzan planned to keep his distance and wear him down.
• Mu Yu chased Muzan Kibutsuji, using Phantom Sun Rainbow - Shave Dance to cut through the Black Blood Thorns blocking his path.
• Muzan Kibutsuji increased his speed with blood demon abilities, but Mu Yu’s gravity reached him through his thorns and tentacles, leaving his body vulnerable.
• Mu Yu slashed Muzan Kibutsuji into fragments and burned him with a fiery attack, making him scream in pain.

Mu Yu overwhelmed Muzan Kibutsuji, who split into thousands of fragments to escape, but Mu Yu tracked and cut down nearly all of them. The chapter ended with Muzan trapped again as Mu Yu summoned meteorites.

• Mu Yu severed Muzan Kibutsuji’s head, but Muzan trapped him with Black Blood Thorn and attacked with a living mass of flesh.
• Mu Yu used Void and Sun Breathing’s Thirteenth Form to evade Muzan’s attacks and strike him down.
• Muzan Kibutsuji split into nearly three thousand fragments and fled in every direction.
• Mu Yu used the Eyes of the Thiên Nhãn to track the fragments and cut down more than twenty-nine hundred of them.
• Muzan reassembled a fist-sized fragment ten thousand meters away, but Mu Yu sensed him and called down meteorites.