Tanjiro Kamado, Nezuko Kamado, Genya Shinazugawa and Mitsuri Kanroji vs Hantengu

Tanjiro Kamado, Nezuko Kamado, Genya Shinazugawa and Mitsuri Kanroji vs Hantengu is a battle that takes place in the Swordsmith Village, between Demon Slayers Tanjiro Kamado, Nezuko Kamado, Genya Shinazugawa, and the Love Hashira Mitsuri Kanroji against Hantengu, Upper Rank Four of the Twelve Kizuki.

Prologue
Following the death of Upper Six demons Daki and Gyutaro in the battle in Yoshiwara, Muzan Kibutsuji summons the remaining Upper Ranks to the Infinity Castle. He relays his anger over having a change amongst their rankings, which had not happened in 113 years, and he admonishes them for their continual failure to either kill the Ubuyashiki family or find the Blue Spider Lily. Upper Five Gyokko then informs Muzan of information he had discovered in an attempt to appease him, and deeming the intel worthwhile, the Demon King orders him and Hantengu, Upper Rank Four, to infiltrate the Swordsmith Village.

Two months after defeating the Upper Rank siblings, Tanjiro Kamado regains consciousness from the severe injuries he had taken in his ordeal. After a week of rehabilitation, he inquires about his Nichirin sword, only to be informed in a letter given by Kiyo Terauchi that his swordsmith, Haganezuka, had refused to make him another one. He travels to the Swordsmith Village with Nezuko to negotiate a weapon to be made for, and subsequently meets the Love Hashira Mitsuri Kanroj i, as well as Genya Shinazugawa, who he recognizes as the third male survivor in his Final Selection. He then enters a nearby forest to train and meets the Mist Hashira Muichiro Tokito.

Leaving a pot in the open for someone to find, Gyokko sucks a swordsmith inside and spits him out after tasting him, confirming that they have entered the hidden village. He hopes that destroying the village will cripple the Corps with a lack of weapons. Elsewhere, Hantengu, fearful of Muzan's wrath, resolves to kill everyone inside to appease him. Muichiro meets with Tanjiro in a house to discuss their swordsmiths. The Mist Hashira, though initially uncaring and aloof, warms up after seeing Tanjiro's kind and helpful nature.

The coward's true strength
Hantengu enters the room and crawls towards the two. Hiding his engraved eyes, Muichiro and Tanjiro do not see what rank he is but immediately know he is an Upper Rank demon. Muichiro attacks the demon with Mist Breathing, Fourth Form: Shifting Flow Slash, though he misses when Hantengu leaps to the ceiling. Using a sword provided to him, Tanjiro uses Hinokami Kagura: Sunflower Thrust to hit Hantengu, but the Upper Rank is able to quickly dodge the attack and land on the floor. Nezuko joins the battle in her awakened demonic form and kicks Hantengu in the hip, stunning him with the impact and allowing Muichiro to quickly behead him. However, knowing of Daki and Gyutaro's unique immunity to decapitation, Tanjiro reminds Muichiro to stay on guard.

Hantengu's severed head suddenly forms a new body, whilst his old body becomes a new demon entirely. As Muichiro attacks the demon in front of him, it uses a maple leaf-shaped uchiwa and blasts Muichiro out of the house with a gust of wind, while Nezuko and Tanjiro struggle to hold on.

The uchiwa-wielding demon, Karaku, talks to the other demon, Sekido about his joy seeing the Demon Slayers struggle in his wind, but the latter only voices his anger at having to be combined with him to begin with. Sekido uses his khakkhara to summon a burst of electricity that incapacitates the Kamado siblings.

"It want you to cut its head off!"
From the roof top behind the demons, Genya suddenly appears and shoots them with a shotgun loaded with Nichirin steel shot, decapitating Sekido but only partially severing Karaku's neck. Genya rushes to the floor and finishes beheading the demon with his sword, only to be warned by Tanjiro to avoid beheading them. Sekido and Karaku heal instantly, and their old bodies become two new demons, now totalling four Upper Rank opponents. Tanjiro is grabbed by the winged demon, Urogi, and flown into the sky; before he is taken away, he tells Nezuko to assist Genya, who is concurrently being attacked by the yari-wielding demon Aizetsu. Genya is unable to dodge the demon and is stabbed in the chest. Tanjiro tries to attack Urogi but is hit by a deafening sonic shriek, only freeing himself by cutting off the demon's leg. He falls into the forest below and lands hard on the ground, but the leg still attached to him forms a new head. Tanjiro cuts it in half, only for the halves to form two mouths and hit him with the sonic attack again. However, he notices that the attack's strength has weakened, realizing the clones all have to share one strength. The healed Urogi slashes Tanjiro with his talons but simultaneously has his head split by the Demon Slayer.

Karaku has Nezuko in his hold; Sekido irritably tells him to quickly kill her but the relaxed demon wants to savour the moment. Genya, while still pinned by the weapon, shoots Aizetsu in the head, but the demon pulls the yari sideways, cutting through Genya's body. Genya seemingly loses consciousness while saying the Amida Sutra, but when Aizetsu tries to kill him, he suddenly appears behind the demon and tries to behead him. However, Sekido stuns him with his lightning, though he is confused at how Genya is surviving such horrific wounds. Having had his fun, Karaku kicks Nezuko and drives his leg through her body. He informs Sekido that he will rip off her limbs and he can use his lightning to kill her, to which the angry demon states that it was his initial plan all along. When Karaku tears off her hand, he is suddenly kicked in the head by the young demon; her blood sprayed all over him then ignites, startling him and Sekido. Holding his hand wielding the uchiwa, she blasts Karaku with his own wind. When she attempt to do the same Sekido, he blitzes her and stabs the khakkhara into her neck, before generating lightning to stun her.

In the forest, Tanjiro struggles to fight Urogi's speed and the thick tress obscuring him. He sees the building with Nezuko and Genya inside in the distance and moves to it; when the demon attempt to swoop in and slash him, he anticipates the move and stabs Urogi in the mouth. They both land back inside the building, where Tanjiro sees Nezuko being shocked. Sekido tries to shock him as well with his khakkhara but Tanjiro uses Urogi's severed foot to prevent the lightning being channelled. He then slices Sekido's tongue, having realized that when their tongues are injured, they heal slower. Tanjiro uses the foot to remove the khakkhara imbedded in her; he is in turned saved when Sekido attempts to stab him behind the neck. Nezuko grabs it before it can go deeper into her brother and sets Sekido ablaze with her Blood Demon Art. Elsewhere at the Swordsmith Village, numerous giant fish demons created by Gyokko rampage through the area, slaughtering sword smiths indiscriminately. Before a group of smiths in the open can be cornered and killed, the Love Hashira arrives and slices the demon apart. One demon attempts to kill village chief Tecchin, having killed the Demon Slayers sent to protect them. Mitsuri appears in the nick of time and slices the demon apart with Love Breathing, First Form: Shivers of First Love.

Tanjiro suddenly sees Karaku in the sky; having healed and now wield a new uchiwa, he hits Tanjiro and Nezuko with a powerful blast of wind, knocking them unconscious with the sheer pressure, leaving a maple-leaf shaped indentation in the floor. Tanjiro regains consciousness and is grabbed by Nezuko to avoid another burst of lightning from Sekido. Urogi tries to swoop in and slash them but the siblings duck out of the way. Sekido orders Karaku to destroy the building, which he does by summon a gust of wind in the interior, blowing up the entire structure. Tanjiro is unharmed but Nezuko is pinned beneath rubble.

Recurring memories
Tanjiro tries to remove the debris but is shocked to see Nezuko grabbing his sword by the blade. She cuts her hands along its edge, coating the sword in her blood, which she ignites. He watches in amazement as the steel begins to turn bright red, similar to the memories he saw of the unknown swordsman. Urogi, Karaku, and Sekido watch as Tanjiro walks towards them by himself, but only Sekido notices that his weapon is now red, similar to the blade of the swordsman who nearly killed Muzan. As the scar on his forehead grows into a fiery mark once more, Tanjiro unleashes Hinokami Kagura: Sun Halo Dragon Head Dance, instantly slicing through the three Upper Rank clones in one fluid move. He recalls the moment when he fought Gyutaro and how he had suddenly gained the strength to cut off his head, how his breathing and body felt like it was burning. To his surprise, he sees Genya close by; Genya had managed to pin Aizetsu to a tree with his yari and beheaded him. When he turns his head however, Genya now has taken on a monstrous appearance, his eyes with black sclera and fangs in his mouth. Urogi and Karaku are shocked at Tanjiro's attack and fearfully believe that their regeneration has stopped, only to be told by a furious Sekido that it is simply slower. Tanjiro sees that despite all four demons now beheaded, they still remain alive and surmises that there is a fifth demon where, having detected its scent briefly.

Suddenly, Genya grabs Tanjiro by the neck, yelling that it will be him who will kill the Upper Rank, and that it was not his own strength that allowed him to beat Gyutaro. Hearing Genya claim that he will become a Hashira, and instead of being upset, Tanjiro voices that he and will Nezuko will help him do so, informing him that a fifth demon to kill is somewhere, surprising Genya with his honest and kind attitude. He then pushes his fellow teammate away as lightning surrounds them, Sekido now fully healed. Elsewhere, Hantengu is cowering in a hidden location, afraid but hopeful his clones of emotion will kill the Demon Slayers.

"This is the main body?!"
Tanjiro tells Genya to head north-east, as well as Nezuko to aid him. Karaku's winds suddenly pummel the area, stalling their attacks. Before Sekido can add lightning to the fray, Nezuko lunges towards him, only to be pinned to a tree by Aizetsu and his yari. Nonetheless, Tanjiro speeds in and slices Sekido and an attacking Urogi apart with Hinokami Kagura; the former is shocked to suddenly see him moving so quickly, noting that he is much stronger than Muzan had described. Nezuko grabs Aizetsu by the head and pulls herself away from the tree, holding onto him to set him on fire.

Karaku then swings his uchiwa at Tanjiro, pinning him to the floor with his wind, but when he attempts to hit Genya, the demon sees his arm suddenly sliced in half. Genya, in the location of the fifth demon, cannot find it till he is told to look down by Tanjiro; he sees Hantengu with a very small body. Hantengu runs away and Genya is barely to able keep up, losing track of him because of his size and speed. He attempts to swing his blade at Upper Four's neck but cannot cut through despite its small width. He then senses Sekido behind him, about to stab his khakkhara into his neck. In the moment, Genya loses himself and reminisces on the major tragedy in his life and the events that led to Sanemi's resentment of him as a Demon Slayer. Tanjiro cuts off Sekido's head to save him in time, the khakkhara's tip just missing his neck. He tells him to try again and reminds him of his desire to be a Hashira. Aizetsu appears behind them and attempts to kill the two with Weeping Spears, projecting long ranges slices of his yari. Genya stands in the way to save Tanjiro, sustaining numerous holes in his body. Conceding his inability to behead the demon, Genya tells Tanjiro to be the one to kill the small demon. Tanjiro uses Hinokami Kagura and makes contact with Hantengu's neck. As he struggles to even cut into the demon, Tanjiro feels something behind him. Genya warns him to move but he is unable to do so with Hantengu pinned to his blade. Nezuko shoves him away as Genya fires at what was behind; immense wooden dragons seemingly spawned by a sixth demon. However, upon looking closer, Tanjiro and Genya note that this new demon is actually the other demons combined as one; he was originally Sekido before undergoing a transformation and had summoned Urogi, Karaku, and Aizetsu to absorb as well. Zohakuten, an manifestation of Upper Four's hatred, wraps the small Hantengu in wood as protection. He curses the Demon Slayers as villains and denounces their actions against Hantengu, claiming they are "bullying" someone weak. Hearing this, Tanjiro seethes with anger and responds by mentioning that from their scent, they have devoured at least 200 innocent lives, swearing to behead the demon in revenge.

A wooden dragon grabs Tanjiro and hurls him into the air; he attempts to use Hinokami Kagura: Clear Blue Sky but the dragon uses Urogi's sonic shriek and disorients him, causing his eardrums to burst and his balance to disappear. The dragon then uses Karaku's winds to pin him down, injuring his leg. He breaks free and tries to run but Zohakuten uses Sekido's lightning to attack. The dragon then grows smaller heads from its mouth, stretch to grab Tanjiro and pull him in to kill; Nezuko and Genya are simultaneously trapped and unable to aid him.

Mitsuri intervenes
Suddenly, the dragon's head splits in half, sliced by Mitsuri and saving Tanjiro. She puts him far away to recover and faces off against Zohakuten. Mitsuri demands the demon release Nezuko and Genya but the demon only insults her, claiming only one person can order him. He uses Crazed Cry of Thunder Death to attack her; two dragon heads launching both the sonic attack and lightning at the Love Hashira. Mitsuri uses Love Breathing, Third Form: Catlove Shower and cuts right through both attacks, shocking Tanjiro and surprising Zohakuten. The Upper Rank attempts to use his winds and pin her down but she uses Love Breathing, Second Form: Love Pangs to strike the dragon. Zohakuten tries to use Weeping Spears to slice her apart but Mitsuri dodges and cuts through the attack with Sixth Form: Catlegged Winds of Love. Deciding that he will instead overwhelm the Love Hashira, Zohakuten summons even more wooden dragons and uses Blood Demon Art: Countless Striking Trees. Unsure if she can withstand a wide-range attack, Mitsuri uses Love Breathing, Fifth Form: Swaying Love Wildclaw and closes in on the demon, wrapping her whip sword around his neck.

Tanjiro warns her that it won't die through decapitation but Zohakuten hits her point blank with the sonic shriek, paralyzing the Hashira. Tanjiro, Nezuko, and Genya push her away from further harm; all three resorting to protecting Mitsuri as the strongest one on the battlefield. Zohakuten summons lightning and strikes around the Demon Slayers. Touched by their act, Mitsuri emphatically declares that the Demon Slayer Corps is important to her and promises not to let anyone die tonight. Remembering that she is valued in the Corps, unlike in her old life, she charges head-on towards Zohakuten and slices the dragons apart. Tanjiro, Nezuko, and Genya run to find the main body; Zohakuten sees and tries to send a dragon to kill them but it is sliced apart instantly.

Shocked to see the Hashira moving faster than ever, he notices a mark on her chest that was not present before. Angered that she alone is killing his dragons, Zohakuten then realizes that she will eventually tire and he can kill them then. Tanjiro, Nezuko, and Genya hand on to the tree containing Hantengu; Genya bites through the wood and absorbs the demon's flesh, gaining strength and regeneration. He chews through and the tree's crown breaks off. The branches then sharpen and try to fend off the Demon Slayers; Nezuko uses her blood and sets the wood on fire, as well as turning Tanjiro's sword bright red again. He uses Hinokami Kagura: Flame Dance and slices the wooden burl apart, only to find Hantengu gone. Seeing the demon flee, Tanjiro angrily declares he would make him take responsibility for his actions; the words remind Hantengu of the times he was reprimanded for his crimes and he denounces them as lies, claiming he is but a good-natured weakling who deserves sympathy. Genya hurls numerous trees at the demon but misses his mark. Hantengu begins to run away and dodges Nezuko's attempts to hit him. Seeing Mitsuri is no longer keeping up with Zohakuten's attacks, Tanjiro resolves to never let them win. Having difficulty in keeping up with his injured leg, he remembers when Zenitsu Agatsuma had given him advice regarding Total Concentration Breathing; one must be full aware of their body in order to achieve full mastery. Recalling his words, Tanjiro breathes in to circulate oxygen into his muscles, builds strength into his legs and blitzes forward with immense speed.

His sword reaches Hantengu's neck but the demon grows his body into a giant manifestation, his resentment. Urami grabs Tanjiro by the head and tries to crush him, angered at his lack of pity towards the "weak". Genya stops the demon's hands from crushing him and Nezuko leaps over Urami to set his ablaze. However, Genya is forced to back away from Nezuko's attack, as her fires will burn him as well. Urami, Tanjiro, and Nezuko fall off a cliff; Tanjiro falls into a tree and Nezuko collapses to the ground. Urami gets up and walks away, seeing his regeneration is slowing due to Zohakuten using much of their shared strength. Seeing swordsmiths in the village, he attempts to eat them to rejoin the fight with the Demon Slayers. Without a sword, Tanjiro gets up and makes his way to the demon, but a sword stabs into the ground in front of him. Muichiro hurls his unfinished blade to help him kill the demon, though Haganezuka is not pleased that it is unfinished.

"This is the end for you..."
Tanjiro grabs the sword and use Dancing Flash, combining Hinokami Kagura and Thunder Breathing to behead Urami instantly. As dawn is about to arrive and in open ground, he realizes the field is dangerous for Nezuko. However, she reaches him and shows that Urami's body is still moving; he sees the kanji on the tongue is Urami's, not Hantengu's, and he has failed to kill the main body. The sun then breaks over the horizon and Nezuko begins to burn. He begs her to shrink her body as protection, seeing that she is burning so badly despite only the break of dawn. He sees Urami running away and looks to the cliff to see Muichiro at the top and Genya forced to flee the sunlight. Without help and with his dying sister in his arms, Tanjiro freezes; Nezuko pushes him away, signifying that he must finish the demon as the light continues to burn her. With Urami close by and watching Nezuko die before him, Tanjiro resolves to kill Upper Four once and for all. He sniffs the fleeing body and discovers Hantengu hiding in the heart of the giant demon. As Urami's body holds swordsmith in his hands, Tanjiro blitzes in front of the demon and demands that Hantengu takes responsibility for his actions, "Now pay for your sins, with your life!". His words reach Hantengu and he experiences his human life flashing before his eyes; all the moments he was arrested, tried, and reprimanded for his actions, as well as the moment he met Muzan. Tanjiro slices the body in half and cuts through Hantengu's neck, killing Upper Rank Four.

Aftermath
Despite the death of Hantengu, Tanjiro drops to the ground and begins to mourn Nezuko's death. As he begins to cry, believing nothing remains of her, a swordsmith implores him to turn around. He sees Nezuko standing before him, no longer burning in the sun. Tanjiro approaches his sister and as if she is alright. Nezuko responds but in a broken way of speaking, saddening Tanjiro that while immune to the sun, she remains a demon. Nonetheless, he pulls her into a hug and is relieved just to see her fine. Genya, no longer with his demonic powers, smiles at the siblings' moment of relief. In the forest nearby, as the dragons converge on Mitsuri, she cries out that she can no longer fight. The dragons attempt to kill the Hashira but suddenly burn into ash. Mitsuri is glad to see that Tanjiro had kill the main body, while Zohakuten is in disbelief of his death.

Elsewhere, in a manor, standing over a messy pile of library books, a disguised Muzan is overjoyed over Hantengu's work. With a demon that has conquered sunlight, he realizes he can too by absorbing her; his pretend mother and a maid watch him curiosuly but he decapitates the former instantly. The maid watches in horror as Muzan grows out of the child's body and into his normal appearance, accusing him of being a monster before she is murdered.