For a long moment, neither moves.
Ren Hajime.
The Hollow King.
The battlefield trembles beneath their silence. The clouds no longer moved naturally. The wind no longer obeyed the sky. Even the air felt diseased, thick and unwilling to flow.
Ren stared at him. The Hollow King stared back.
An endless abyss looked through ruined crimson eyes.
His aura was not merely powerful… it was wrong, ancient, malevolent. As though something buried beneath creation itself had finally opened its eyes.
The Hollow King observed him.
"So calm..."
His voice sounded distant, layered with something older than language.
"Even standing before me… What kind of god are you?"
The darkness around him rippled.
And suddenly—
A memory surfaced.
Neither from Ren nor from Jigen. From the Hollow King.
———————————————————————
Around 50 years ago.
Under the Full Moon.
The night sky glowed silver.
Jigen's body stood motionless beneath the moon. Countless divine weapons pierced his flesh—
His chest. His stomach. His shoulders. His neck. His limbs.
Blood flowed endlessly, staining the earth black-red. Yet he remained standing, silent.
Above him floated Eliza.
No… Not the Eliza known today. Something far more divine.
Her white hair flowed like liquid moonlight unlike her usual black hair. Eight enormous angelic wings stretched across the heavens. Her skin radiated a sacred glow. Ancient ornaments shimmered around her body.
A celestial crown floated above her head. The full moon itself seemed dim beside her.
She looked less like a demon and more like a goddess that had descended from another world.
Yet her sapphire eyes contained anger… and fear.
Her voice echoed across the night.
"No matter how many times I destroy you… You never die."
A giant celestial sphere formed behind her.
A divine pentagram expanded across the sky. Reality bent beneath its pressure.
"What do you want from me?! What have I done to deserve death?"
Silence.
Then—
A low, animalistic sound emerged from Jigen's throat, something that did not belong to any living creature.
Eliza's eyes narrowed.
No… This isn't him. He's not that devil… So, who is exactly him?
Her grip tightened around her staff.
A chill crawled through her immortal soul.
"Who… Who are you?"
The weapons embedded inside him shattered. One by one. Without being touched, without force, without explanation.
Crack. Crack. Crack.
The sound echoed through the night. Jigen's ruined body began walking, slowly, casually.
Like a corpse remembering how to move.
Then his head rose. Pure black retinas, crimson irises. Blood streaming from his eyes. Blood dripped from his mouth.
The moonlight seemed to recoil from his face.
Eliza's expression changed. For the first time, she felt fear. Not fear of death, but the fear of existence.
"I can feel it..." Her voice trembled. "His presence..."
The celestial sphere behind her expanded. The divine pentagram illuminated the entire world. Her staff shone brighter than the stars.
"It makes me sick."
The sky itself began shaking.
"I cannot allow something like this to exist."
She raised her staff. The heavens gathered around her command. And then—
He vanished.
Eliza's pupils shrank.
When—
A figure stood before her instantly, as though distance had refused to exist between them.
Her breath stopped.
The Hollow King's gaze met hers, cold, empty, ancient. Like a predator observing an insect.
Then he spoke, his voice absolute, ruthless.
"You call yourself a god." His ruined lips barely moved. "Yet you still ask why you deserve death…"
His fist moved.
SMASH.
The impact never reached her.
Her staff exploded first.
Then the celestial sphere. Then the pentagram. Then every divine construct she had summoned— All erased. As though reality itself rejected their existence.
Eliza's eyes widened.
For the first time in centuries, she felt small.
———————————————————————
In the present time.
The memory shattered.
The Hollow King took a single step.
The battlefield shook. Mountains cracked. The clouds split apart.
Then—
He moved.
Too instant that the distance simply ceased to exist.
Ren's eyes widened. The Hollow King was already in front of him.
A fist descended.
Ren immediately shifted his blade. The angle perfect, the position flawless.
BOOM.
The impact detonated across the landscape. The earth collapsed beneath Ren's feet. Shockwaves tore through the horizon.
Yet Ren survived.
He slid backward across the ground. His muscles tightened, his grip remained firm.
The Hollow King watched him. For the first time, a trace of interest entered his gaze.
"He blocked my attack…? Unlike that bitch whom I thought to be a god… he's way stronger…"
The Hollow King slowly raises his arm. The sky reacts first.
Dark clouds twist unnaturally above him, spiraling toward his hand as if the heavens themselves are being dragged into a black hole.
Thunder erupts. The violent winds stop obeying nature. Mountains tremble. Trees bend. The atmosphere itself seems to collapse inward.
Dark smoke pours from the horizon, coiling around his arm like living serpents.
The sky bends completely, as though reality itself is being pulled toward him.
The Hollow King watches. Silent. Observing. Judging.
Then—
"SUN BREATHING... FIRST FORM!"
Ren vanishes.
A crimson flash tears through the battlefield.
SLASH.
The Hollow King's head is severed. Both arms are severed. The cuts are perfect. Absolute. Yet—
Nothing falls.
The severed pieces remain suspended. The head slowly turns. The detached hands slowly close. Then, without regeneration… without healing… without explanation… They simply reconnect.
As if the concept of being cut apart no longer applies to him.
The Hollow King's gaze settles upon Ren. His voice emerges, cold, ancient, malevolent.
"Was that your triumph…? How fragile your standards have become…."
The clouds split apart.
The Hollow King rises into the sky. Not flying, but ascending. Like something returning to a throne that once belonged to it.
Ren narrows his eyes. The darkness above begins moving. Then—
The sky opens. A colossal shadow dragon emerges from the abyss above. Its body stretches beyond the clouds. Beyond the storm, beyond sight itself.
Its scales resemble moving darkness. Its eyes resemble dying stars. Its existence alone turns daylight into twilight.
The Hollow King floats before it. A crimson pentagram unfolds behind him. Alive. Pulsating. Breathing. Watching.
The dragon coils around the heavens. The storm becomes its heartbeat.
The Hollow King speaks.
"I mistook you for a god..." His crimson eyes stare into Ren.
"But you are merely a mortal standing above gods."
Then—
The dragon descends. The entire sky falls with it.
Ren remains motionless, calm, steady. Even as the shadow of annihilation swallows the battlefield.
"SUN BREATHING... SECOND FORM..."
Ren launches upward.
The dragon opens its jaws. The Hollow King appears above him. Distance ceases to exist.
Ren is trapped between both monsters.
The dragon below. The Hollow King above.
"...CLEAR BLUE SKY."
Ren spins.
Solar flames erupt. A perfect circle of destruction.
The dragon's head separates instantly. The heavens ignite. The clouds are sliced apart. The storm itself is severed. But—
The Hollow King's hand grabs Ren's wrist.
His grip feels less like flesh, more like being seized by an abyss.
Ren's eyes widened.
The Hollow King immediately drives him downward. The landscape rushes upward. The ground prepares to shatter.
"How—" Ren's thoughts stop. "How did he become this strong?"
Before impact—
Ren twists. His body rotates.
A spinning kick crashes into the Hollow King's neck.
BOOM.
The grip loosens. Ren immediately draws his blade.
"SUN BREATHING... THIRD FORM..."
His sword ignites.
"RAGING SUN!"
SLASH. SLASH. SLASH.
The strikes arrive faster than sound. Faster than thought.
The Hollow King's torso splits apart.
His chest opens, ribs shatter, organs are exposed. Yet—
He simply changes direction mid-air. As though his ruined body means nothing.
Both land upon the battlefield.
Silence follows.
The Hollow King stands. His body is a disaster—
Skin hanging. Organs exposed. Bones visible. Burning wounds covering every inch of flesh. Yet he remains perfectly upright… As if pain itself has no authority over him.
He slowly touches the blood running from his chest. The blood drips across his fingers. He studies it for a moment. Then brings it to his lips and tastes it.
"So… this is how that bastard tastes like…"
Ren's eyes narrow, his chest rising and falling faster. "This guy… He's not him… Jigen was already a big shot, but is there even someone much worse than him…?"
The Hollow King slowly buries his fingers into his own shoulders. Deep, past muscles, past bone.
Then tears away chunks of his own ruined flesh. Wet tearing echoes across the battlefield. He looks at the exposed wounds, observing them. As though experiencing a forgotten sensation.
"It makes me crave more for blood… More for destruction…"
The atmosphere becomes heavier.
Ren suddenly freezes. A sharp pain erupts behind his eyes.
Blood drips from his nose.
His vision blurs. For the first time in years, his composure wavers.
He looks at his trembling hand. "What...?"
His pupils contract.
Even standing still… Even doing nothing… The Hollow King's presence is crushing him.
At last, the Hollow King's gaze settled upon Ren. His ruined eyes glowed crimson, ancient, malevolent.
The storm above seemed to freeze.
"You resemble that swordsman…"
Reality itself seemed unwilling to hear him speak.
Ren narrowed his eyes. "Swordsman?"
The Hollow King's head tilted.
"That pathetic demon who wields a sword… I thought he was good enough, but even he was another brat…"
———————————————————————
Around 50 years ago.
At the same night.
Kokushibo stood motionless. His six eyes were wide.
Not with fear. Kokushibo did not fear easily. But disbelief… Pure disbelief.
His shattered blade lay before him. Smoke rose from the fragments. The weapon that had survived countless battles is destroyed in a single strike.
Jigen knelt nearby.
Blood streamed endlessly from his eyes.
From his mouth. His body trembled. As though fighting something within himself.
Kokushibo stared, his six eyes observed every detail, every movement, every breath, every drop of blood.
Then he spoke, slowly, carefully.
"It was not you…"
Silence.
"It was another existence." His voice deepened, even Kokushibo seemed disturbed.
"I did not lower my guard." His eyes fell upon the broken sword.
"I perceived the attack… I reacted. "And yet..."
His six eyes narrowed.
"That thing shattered my blade as though my strength was meaningless."
The night remained silent. Even Kokushibo could not fully comprehend what he had witnessed.
———————————————————————
Now, in the present time again.
BOOM.
The battlefield exploded. The Hollow King launched forward.
Faster. Far faster.
Darkness folded around him. Space warped. The storm followed behind him like a cloak. A black sphere formed between his hands, something darker, something that seemed to consume light itself.
Ren immediately felt it.
The pressure. The wrongness.
The Hollow King appeared before him. Instantly. His target was not Ren. It was the sword.
Ren understood immediately, and moved.
"SUN BREATHING... FOURTH FORM..."
The world flashed gold.
"BURNING BONES, SUMMER SUN."
Ren vanished.
The Hollow King struck empty air. Then—
SLASH.
SLASH.
SLASH.
SLASH.
SLASH.
Countless crimson arcs tore through his body.
His chest opened. His shoulders split. His spine shattered. The black sphere disintegrated. His flesh twisted unnaturally. Yet—
The Hollow King did not stop. His body continued moving, as though damage no longer held meaning.
His broken torso rotated. His ruined limbs bent. His destroyed muscles moved regardless.
And he lunged again.
———————————————————————
Around 150 years ago.
At dark night.
Muzan Kibutsuji stood beneath the moon.
The Demon King.
The First Demon.
The Origin of Terror.
His presence alone was enough to make lesser demons collapse. His eyes watched the figure before him, cold, judging.
"People like you are only best when they're demons… In the end, you had to accept my offer." A wicked smile curls his lips.
Before him stood a figure, bent. Motionless. Watching.
Not Jigen… something else. Something hidden behind Jigen's flesh.
Darkness leaked from his body. The ground blackened beneath his feet.
His eyes were black, only crimson irises remained. Blood streamed endlessly from them. An inhuman growl escaped his throat.
Then—
The Hollow King looked directly into Muzan's eyes. The atmosphere changed instantly.
Muzan felt it. For the first time in centuries, something stared back.
Not as prey, not as servant, not even as an equal.
Something older… Something infinitely hostile.
Muzan's veins pop up, his eyes narrowed. "What are you doing.?! Do you dare to look right into my eyes…?! You pathetic creature."
The Hollow King spoke, his voice sounded ancient. Like words dragged from a dead universe.
"You call yourself king… But your kingdom is built upon insects."
Muzan's expression darkened.
He can sense it. Jigen's aura is infinitely more overwhelming and evil than Muzan's aura.
Muzan's fist clenches. "How dare you?!! I thought you'd be my greatest demon… Even someone better than Ashkaroth or Kokushibo, but you've crossed your limit."
Muzan steps forward, lifting his arm. "You deserve to die, you miserable existence."
The world blurred.
In an instant—
The Hollow King moved. The distance simply ceased to matter.
SHRRRK.
Muzan's body split open.
Blood erupted. His old scars— the wounds Yoriichi had carved into him centuries ago. Every one of them reopened simultaneously.
Muzan's eyes widened impossibly.
Nobody knew where those wounds truly were. Yet this thing had found every single one. As though it could see straight through flesh. Straight through memory, through the soul.
———————————————————————
In the present time.
The Hollow King remained airborne.
His claws descended. The same claws that once tore through Muzan.
But Ren moved first.
He flipped backward through the storm. Golden flames erupted.
"SUN BREATHING..." The darkness shook.
"FIFTH FORM..."
Ren's blade flashed.
"SETTING SUN TRANSFORMATION!"
SLASH.
The Hollow King's neck separated. Both hands followed. The cuts were flawless. His body fell apart. Yet before the pieces could touch the ground—
They reattached. No regeneration, no healing. They simply became whole again as though reality refused to acknowledge his injuries.
Ren landed, his expression sharpened.
"He's even faster than before… He's getting stronger every minute. I need to kill him before he surpasses me."
The Hollow King slowly turns toward Ren.
The storm circles around him. Darkness bleeds from his body. His crimson eyes glow within the abyss.
"I see." His voice is ancient, cold.
"You protected the world instead of yourself… Or else you could've dodged me..."
The winds stop. The sky darkens further.
His gaze remains fixed on Ren.
"Compassion is merely weakness pretending to be virtue."
Then—
He vanishes. The atmosphere ruptures.
The Hollow King appears above Ren. His dark silhouette eclipses the heavens.
He raises his leg. Slowly. Deliberately.
And Ren sees it.
Billions of shadows. Billions of dead things. The countless abominations he had destroyed. The cosmic entities. The ancient horrors. The five strongest beings the Hollow King had summoned.
Ashkaroth.
Maharaurava.
And countless others.
Their powers, their hatred, their existence. All compressed into a single strike.
For the first time—
Every instinct within Ren screams.
DODGE.
His body moves instantly. The kick misses him by inches. Then—
The Hollow King's foot touches the ground.
Silence for one second.
Then—
BOOOOOOOOOOOOOOOOOOOOMMMMMMMMMMMMMM!!!!
The world detonates.
The continent disappears.
The earth caves inward. Mountains vaporize.
Oceans rise into the sky.
The atmosphere tears apart.
The shockwave circles the planet.
Every nation feels it. Every living creature freezes.
The heavens turn crimson. Thunder screams across the globe.
Far away—
The Infinity Castle violently trembles, its endless corridors shake. Walls crack. Demons stop breathing.
Far away—
The Demon Slayer headquarters shudders. The earth beneath their feet groans. Nobody understands why. Nobody understands what happened.
But every living thing feels it. Something terrible has awakened.
Minutes later.
The battlefield no longer exists. A wound stretches across the world.
Thousands of kilometers wide.
Thousands of kilometers deep.
The crust is gone. The mantle is gone. The planet's burning core is exposed.
An open wound in reality itself.
Molten oceans churn below.
Entire mountain ranges are gone. The horizon itself has disappeared.
Ren stands upon a fragment of broken earth. Motionless. Silent. His eyes remain fixed forward.
Even he cannot immediately comprehend what he is seeing.
Then, the Hollow King begins walking, calm, unhurried. As if strolling through a garden.
The burning core illuminates his blood-soaked body from below. His silhouette resembles the end of existence itself.
"See… You cannot save everything. Not in my presence… Eventually all the species will perish."
His gaze drifts across the burning world.
"This impact alone will doom millions… or billions."
His eyes return to Ren.
"And this was merely an accident."
Ren's hands slowly tighten, his knuckles crack. The veins in his arms bulge.
The Hollow King continues.
"This is not my full strength." The darkness around him expands.
"This is not even a demonstration… This is merely what happens when I exist."
The world falls silent. Then—
A voice interrupts him, cold, sharp, dangerous.
"What did you do…?!"
The Hollow King pauses for the first time.
Nonetheless, the Hollow King continues. "I can sense despair from you… It smells good… Are you scared, mortal…? It reminds me of older worlds. They all looked beautiful in their final moments."
Ren's voice comes again, more terrifying, unrestrained.
"I said what the hell did you do?!!" Ren's voice is cold, unrestrained.
The kind of voice used by a man standing at the edge of violence.
The Hollow King narrows his eyes. For the first time, something feels wrong.
Ren slowly raises his sword. White light begins flowing through the cracks of the apocalypse.
The exposed core. The burning sky. The crimson darkness. Everything reflects within his eyes. His voice becomes absolute.
"You destroyed the lives of people who had nothing to do with us."
The air vibrates.
"You destroyed this world… I never thought that someone could be worse than this, as if Jigen and Muzan weren't enough…
You bastard!"
The flames around his blade begin changing, growing denser, brighter, more dangerous.
The Hollow King watches carefully. A strange sensation appears within him.
He thinks. "Wait… His aura has completely changed. I have never sensed danger from any god, demon, or anything… But this mortal, he's getting on my nerves… For the first time, I can sense danger…"
Ren takes a single step forward.
The world shakes. Not because of power, because of intent. The kindness is gone. The mercy is gone.
Only conviction remains.
"In our battle, you shouldn't have damaged this world… Why don't you bastard listen?"