Chapter 18: Muzan Kibutsuji’s Plan to Turn Nobles and Royals into Demons
For a brief moment, everything in their surroundings was engulfed in a crimson glow.
However, none of the Hashira panicked. Instead, they each unleashed their defensive sword techniques.
"Flame Breathing: Fourth Form - Blooming Flame Undulation!"
"Water Breathing: Tenth Form - Constant Flux!"
"Stone Breathing: Third Form - Stone Skin!"
Even those whose Breathing Styles lacked a dedicated defensive form were able to deflect the incoming crescent-shaped blood blades with blindingly fast strikes.
Clang! Clang! Clang!
The deafening clash of blades and demonic blood echoed like a storm of fireworks. What few blood blades managed to evade their defenses crashed into the surrounding structures, shredding wooden buildings into splinters and leaving the area in ruins.
The destruction spread rapidly. Unlucky civilians attempting to extinguish the fires were caught in the attack's aftermath. Screams and cries of anguish intermingled with the relentless crackling of flames.
"Impossible! My strongest technique—how could it not force them to retreat even a single step?!"
Gyutaro, aiming to break through the encirclement, froze as his eyes widened in disbelief. His pupils contracted into thin slits, and blood vessels bulged grotesquely in his sockets.
"No way... there's no way! Are all these slayers stronger than me?!"
He quickly dismissed the thought. "No, it's not all of them—it's those three! Those three are different from the rest!"
Their aura was suffocating, overwhelmingly strong—far beyond the rest. Not only did they fend off his attacks, but they also had the capacity to cover their comrades.
"I have to escape! My sister's head has already been severed. If mine is cut off as well, we're finished!"
His desperation mounting, Gyutaro sprang into action.
Flee!
He lunged toward the weakest-looking slayer in the group, hoping to create an opening.
"Blood Demon Art: Flying Blood Scythes!"
"Water Breathing: Eleventh Form - Dead Calm."
Giyu Tomioka's voice was calm, his expression blank as his sword cut through the air.
In an instant, an intangible stillness spread outward, neutralizing everything in its reach.
"What?! My Blood Demon Art... it's gone!"
Gyutaro's blood blades disintegrated into harmless liquid droplets before they could even touch Giyu.
"Water Breathing: First Form - Water Surface Slash."
Giyu seamlessly followed up, his blade flashing.
"My hands!" Gyutaro howled as both his arms were severed in a single clean stroke.
Before he could process the loss, another attack came hurtling toward him.
"Stone Breathing: Second Form- Upper Smash!"
Blind yet unyielding, Gyomei Himejima leaped forward, his meteor hammer crashing into Gyutaro's chest with crushing force.
The demon's body crumpled like a ragdoll, hurtling through the air and slamming into the remains of a wooden building. The structure collapsed with a resounding crash, burying him in debris.
"Flame Breathing: Fifth Form - Flame Tiger!"
Kyojuro Rengoku charged forward, his flaming blade carving a blazing path. The Nichirin sword pierced Gyutaro's chest, pinning him to the ground like a nail driven through wood.
"AAAAAAH!" Gyutaro's anguished scream tore through the air as his grotesque features twisted in pain.
"Too fast… their attacks are too fast and relentless. I can't react in time—this is the end!"
Despair gripped Gyutaro as he realized his predicament. "Muzan-sama, forgive me!"
"Don't give him a chance to recover—cut off his head now!" Sanemi Shinazugawa roared as he surged forward, his blade aiming for Gyutaro's neck.
Clang!
The metallic sound echoed sharply. The neck of an Upper-Rank demon was far tougher than any Lower-Rank's, its hardness comparable to steel.
"AAAAAH! GET OFF ME!"
Gyutaro's face twisted in rage. The veins across his body swelled grotesquely, his skin splitting open as he attempted to unleash another "Rotating Circular Slash."
However, Kanae Kocho's Nichirin blade struck him before he could act. The sword emitted a faint scent of wisteria flowers, and with it, a shimmering illusion of wisteria blossoms enveloped Gyutaro's body.
"HRAAAAAH!"
Crack!
Unable to resist any longer, Gyutaro's head was severed cleanly as though slicing through tofu.
His face froze in terror, incapable of uttering another word. As his vision blurred, his gaze fell on his sister Daki's severed head being kicked toward him by a woman.
Sanemi spat on the ground, his voice laced with disdain. "Tch, even for a demon, their necks are absurdly tough."
"Ah, that was way too easy. I barely even got to do anything—I didn't even land a single strike," Tengen Uzui said, stretching his back with a bored expression.
"Didn't you start the fire, though?" Giyu interjected dryly.
"Hey, I didn't want to start a fire, okay? I had no choice. You really need to work on your phrasing, Giyu." Uzui retorted, clearly annoyed.
"While setting fires is definitely wrong, it did save a lot of lives," Shinobu Kocho chimed in. "Without it scaring off the tourists, that demon's Blood Demon Art would've caused massive casualties."
"So, what's the next move?" Giyu asked, his expression as stoic as ever.
Sanemi glanced at the two severed demon heads, which were disintegrating at an agonizingly slow pace. "Why aren't these heads gone yet?"
"Upper-Rank demons are far stronger than the others," Kyojuro Rengoku explained. "It makes sense their heads take longer to disintegrate."
"I wonder what cutting off Muzan Kibutsuji's head will feel like," Sanemi said, eyes gleaming with eagerness.
"Don't worry. The rest of the Corps is out there exterminating demons as we speak," Uzui said, patting the 'Vision' hanging at his waist. "Lady Fox Spirit gave us fifty of those paper cranes."
"Yeah, those cranes will track down any demon without fail. Even if Muzan's hiding in that so-called Infinity Castle, once most of the demons are dealt with, all the cranes will point to one location."
"Exactly. If Muzan is still somewhere on this land, it's only a matter of time before we find him."
"And I'll be the one to take the first swing," Uzui declared confidently.
Meanwhile, Daki's screams rang out.
"Brother! How could you let this happen? You're so strong—how could they kill you? And now I'm going to die too!"
"I'm strong, but I can't fight eight Hashira at once! Do you think I wanted my head cut off?!"
"What do you mean 'can't fight eight'? You've eaten fifteen Hashira! Eight shouldn't be a problem unless you're just useless!"
"Oh, shut up! You've eaten seven Hashira yourself and still couldn't handle one! Who's useless now?!"
"This is all your fault! If Muzan-sama abandons us, it's because of you!"
"My fault?! If it weren't for me, you'd have been dead long ago—"
"Enough. Both of you," Shinobu crouched down and coldly addressed the bickering demon siblings. "You're both about to die anyway."
Daki and Gyutaro froze in silence as Shinobu's sharp gaze pierced through them.
"Muzan Kibutsuji," she said, her voice calm yet unyielding, "we know you can receive the memories of your dying demons."
"Soon, the Demon Slayer Corps will cut off your head. As long as you remain on this land, you won't escape. Not even that so-called Infinity Castle will be able to stop us."
Kyoto
The Infinity Castle
Crack.
The vial in Muzan Kibutsuji's hand shattered.
"Another failure."
He no longer kept track of how many times his experiments had ended in failure. Frustration churned in his chest, an incessant storm brewing alongside a nagging thought he could not shake.
He thought back to that moment a thousand years ago, when he had killed the doctor who had attempted to cure him. A pang of regret gnawed at him.
He regretted killing the doctor before fully understanding what the Blue Spider Lily truly was.
For centuries, he had scoured medical texts from across the country and beyond, but not a single record of the Blue Spider Lily existed.
"Damn it... even after five hundred years, the injuries that wretch Yoriichi inflicted on me haven't fully healed."
Muzan clutched his chest, which still throbbed faintly with pain.
He had endured for centuries, biding his time until Yoriichi Tsugikuni—the greatest Demon Slayer to have ever lived—had finally succumbed to old age.
Yoriichi's death should have marked the end of Muzan's suffering. He had severed Yoriichi's legacy and perfected his Blood Demon Art: Infinity Castle, granting him what he thought was an unassailable fortress.
And yet, his nightmares had resurfaced.
Gods.
The emergence of gods had shifted everything. A mere blessing from these deities had allowed the Demon Slayers to surpass even Yoriichi's strength.
To avoid detection, Muzan had cut all ties with his demons, ceasing all activity outside the Infinity Castle. He had stopped making new demons entirely.
Creating demons had always served one purpose: to gather information and carry out his will. But now, reflecting on centuries of effort, he found it all futile.
How many demons have I created over the past thousand years? None of them ever brought me anything of value.
For the first time, Muzan doubted his methods. Had his obsession with creating demons been a mistake? Without them, there would have been no Yoriichi, no Demon Slayer Corps, and no gods descending to challenge him.
The more he dwelled on these thoughts, the angrier he became.
From the moment Yoriichi had invented the Breathing Styles that allowed humans to fight demons, the Demon Slayer Corps had grown in power. To become a Hashira, a Demon Slayer had to slay one of his Twelve Kizuki—proof of their prowess.
It was an insult.
The Twelve Kizuki—his most prized creations—reduced to mere stepping stones for the Demon Slayer Corps.
As he seethed, Gyutaro's death flooded Muzan's mind through their shared connection.
The memory unfolded within him.
At first, Muzan felt no panic. The loss of an Upper Rank was insignificant in the grand scheme.
He had already abandoned the demons outside the Infinity Castle.
The hunters blessed by the gods were far stronger than Yoriichi. Slaying an Upper Rank for them was as simple as cutting through weeds.
Even if every demon were exterminated, Muzan would feel no loss. To him, those demons were failures—tools that had only ever brought him trouble.
If not for the risk of exposing himself, he would have killed them all personally.
But as Gyutaro's memory fully unraveled, a chill ran through him.
The Demon Slayers knew about the Infinity Castle.
Muzan froze.
A dreadful clarity took hold.
It must be the gods. They told the Demon Slayers. And those paper cranes they keep mentioning...
Muzan couldn't be certain whether these "paper cranes" could locate the Infinity Castle, but the fact that its existence was known meant his sanctuary was no longer secure.
"If they kill every demon, or even reduce their numbers below fifty, my location will be exposed!"
He clenched his fists, uncertainty and fear clawing at him. The Demon Slayers might be bluffing, but Muzan couldn't afford to gamble.
"As long as I remain on this land, they will find me…"
Terror consumed him.
He didn't doubt it for a second—not with gods watching over the Demon Slayers.
Infinity Castle
Cold sweat dripped steadily from Muzan's face, splashing onto the floor as he paced the vast emptiness of the Infinity Castle. The sound of his footsteps echoed in the silence, filling the void.
"It seems there's only one option left."
He tugged at the brim of his hat, his indifferent gaze shifting to the biwa player, Nakime, standing nearby.
"Die."
"Huh…?"
The curse embedded within Nakime's body activated instantly. Her flesh swelled grotesquely, twisting and contorting as her eyes bulged unnaturally, fixating on Muzan with a mix of shock and despair.
"L-Lord Muzan…"
"The Infinity Castle is useless to me now, and so are you," Muzan said coldly.
Though he was the progenitor of all demons, Muzan was a coward at heart, with no sense of dignity befitting a final boss.
Internally, he regarded demons solely as tools—disposable instruments to be discarded at the slightest provocation. If they displeased him, they died. If they leaked information, they died. If he simply felt annoyed, they died.
Nakime, even as Muzan's most loyal retainer, knew this truth better than anyone. Her grotesquely twisted gaze reflected her resignation.
She understood Muzan's nature all too well: a tyrant devoid of compassion, whose paranoia and rage knew no bounds.
Even the Twelve Kizuki, his elite, were not exempt from his cruelty.
She could not fathom what had angered him this time.
But there was no time to ponder. Her death was imminent.
With Nakime's demise, the Infinity Castle began collapsing rapidly.
Muzan emerged in a dense forest, pulling the brim of his hat lower to conceal his face. His blood-red eyes glimmered with malice from beneath the shadowed brim as he gazed toward a bustling city.
"If the number of demons drops below fifty, they'll find me… Then, before I leave this land, I must create more demons."
He had resolved to flee—to abandon this country and cross the seas to foreign lands.
Surely, the gods wouldn't exist on the other side of the ocean.
But before his escape, Muzan needed to ensure the Demon Slayers were preoccupied. He would create chaos by spawning countless demons, forcing the hunters to divert their focus.
Their attention would inevitably turn toward protecting humanity, leaving them no time to pursue him.
In the past, he had refrained from creating too many demons. Drawing the attention of the nation's rulers or military forces would have been detrimental to his survival.
He had ordered his demons to feast in secrecy, ensuring their existence remained hidden.
But now, the fewer demons there were, the greater the risk to him.
Demons needed to multiply. Chaos needed to reign. Only then could he ensure his escape.
As for the nation's royalty and aristocrats…
"I'll turn you all into demons. Whether it's the gods or the Demon Slayer Corps, none of you will have the time or power to stop me."
A twisted smile crept across Muzan's face.
Why hadn't he thought of this before?
If he had transformed the royals and nobles into demons from the start, he could have mobilized the country's resources to search for the Blue Spider Lily.
By the time he became the perfect being, even the might of a nation would pose no threat to him.
After all, he could always alter his appearance or gender. No one would suspect him of being the demon king who had turned the country's elite.
Tokyo
Chiyoda District
Imperial Palace
Katsura Detached Palace
The reigning emperor of the land paced within his chambers, pondering strategies to wrest power from the feudal lords and reform the nation's governance.
He envisioned transforming the country into a war machine capable of securing a slice of the pie as European powers carved up the Qing territories.
"Those damned regional nobles, that accursed shogunate… Even though I am this nation's emperor, I have no authority over the military."
The emperor's frustration boiled over as he muttered to himself.
Suddenly, a rich, magnetic voice resonated from behind him.
"Do you desire power? I can give you strength."
"Who's there?!"
Startled, the emperor turned to look, but before he could complete the motion, a single finger pierced the back of his skull.
"Ahhhhhh…"