SWISH!
The Nichirin Blade stopped less than an inch from the tree.
Perrin held the position.
His arms trembled.
Sweat ran from his forehead, down his jaw, and disappeared beneath the collar of his training clothes.
He inhaled.
Slow.
Controlled.
Then—
SWISH!
The blade moved again.
"Death Breathing..."
His right foot slid backward.
His shoulders lowered.
"Third Form—"
DANG!
Perrin froze.
The sword stopped halfway through the motion.
"...Seriously?"
A translucent screen opened in front of him.
MISSION GENERATEDELIMINATE LOWER RANK FIVE — RUI
Time Limit: 9 Hours
Objective: Eliminate Rui before the incoming Demon Slayer Corps forces suffer catastrophic casualties on Mount Natagumo.
Current Demon Kill Progress: 1/3
Rewards
+5% Pezo (Human) Template Progress
Random Skill — Deep Ones
The Deep Ones are members of Pezo's future army.
Failure Consequence
UNKNOWN
Perrin stared at the final word.
"...Unknown."
He hated that word.
Unknown could mean nothing.
Unknown could mean losing the mission.
Unknown could also mean waking up without an arm.
With this System?
Perrin wasn't interested in finding out.
"Rui..."
His grip tightened around the Nichirin Blade.
"Lower Rank Five."
Images from his old life immediately returned.
White skin.
Red markings.
Threads.
Mount Natagumo.
Tanjiro nearly dying.
A Nichirin Blade breaking against threads that looked thin enough to snap between two fingers.
And the fake family.
Perrin exhaled.
"Yeah."
He sheathed his sword.
"This is going to suck."
Another message appeared.
SYSTEM REMINDER
Higher Pezo Template percentages require greater demon hunting progression.
Continue eliminating demons to accelerate Template development.
Perrin stared at it.
"Very motivational."
No response.
"Love the encouragement."
Nothing.
Perrin sighed.
"Fine."
He checked his equipment once.
Nichirin Blade.
Supplies.
Nothing unnecessary.
Then he moved.
08:47:16
Perrin ran through the forest.
Trees blurred past him.
Five years of brutal training had been nothing compared to what came afterward.
The System had changed everything.
The Pezo Template had changed everything.
His body wasn't the same body that had nearly died to a nameless demon while holding a wooden sword.
Not anymore.
45%.
Not even halfway.
Yet every percentage had made the difference harder to ignore.
His balance.
Reaction speed.
Strength.
Awareness.
Adaptation.
And eventually—
Death Breathing.
Perrin jumped over a fallen tree without losing speed.
Rui.
He remembered enough.
Rui wasn't alone.
Calling the demons on the mountain a family was generous.
Mother.
Father.
Elder Brother.
Elder Sister.
And Rui.
Rui called himself the youngest son.
But he was the one everyone feared.
The one holding the entire fake family together.
Not through love.
Through terror.
Perrin's expression tightened.
"And the Demon Slayers are walking straight into it."
He accelerated.
07:58:42
Perrin stopped.
Mount Natagumo stood ahead.
Webs stretched between distant trees.
Some were barely visible beneath the moonlight.
Others covered entire sections of the forest.
Perrin's hand moved toward his sword.
"Here we go."
He stepped into the mountain.
One step.
Two.
Three.
Something moved above him.
Perrin looked up.
Tiny spiders crawled along a branch.
White bodies.
Small colored markings.
His eyes narrowed.
"...Mother."
TWANG!
Perrin moved.
A thread sliced through the space where his neck had been.
Another came from behind.
He twisted.
SWISH!
His Nichirin Blade severed it.
More descended from the trees.
Not aimed directly at him.
Moving somewhere else.
Perrin followed them with his eyes.
Then he heard screaming.
"GET IT OFF!"
Perrin's expression changed.
Someone was already here.
A man stumbled between the trees.
Not a Demon Slayer.
A traveler.
Thin white threads were attached to his arms.
His legs jerked unnaturally.
Behind him—
another body.
Dead.
Its head hanging at an impossible angle.
Still moving.
Perrin drew his sword.
"So I wasn't early enough to stop everything."
The corpse rushed him.
Perrin stepped aside.
Its arm swung.
Perrin cut through the threads controlling it instead of the body.
SNAP!
The corpse collapsed.
The living man fell with it.
"What... what is happening?!"
"Run downhill."
"What?"
"Don't stop."
Another thread descended.
Perrin cut it.
"GO!"
The man ran.
Perrin looked upward.
Threads.
Dozens.
They spread farther into the mountain.
Perrin smiled without humor.
"Found your trail."
He disappeared into the trees.
She saw him coming.
The Mother Spider Demon pulled harder on her threads.
"What is that?"
Her fingers moved.
More puppets changed direction.
Perrin came through the trees.
Three bodies attacked simultaneously.
He ducked beneath the first.
Turned around the second.
Blocked the third.
His eyes followed the threads.
Not the puppets.
The threads.
"Death Breathing."
His feet shifted.
"Second Form..."
His sword disappeared into a chain of rapid movements.
COLD REPOSE!
SNAP! SNAP! SNAP! SNAP!
Threads fell apart around him.
Every puppet collapsed.
Mother stared.
"What...?"
Perrin was already moving again.
She pulled her hands back.
A massive body dropped between them.
No head.
Bladed arms.
Perrin stopped.
"Oh."
The headless puppet rushed him.
Its arm tore through a tree.
Perrin jumped backward.
BOOM!
Wood exploded.
"Right."
The second blade came down.
Perrin blocked.
CLANG!
His feet dug into the earth.
"That's..."
His arms shook.
"...stronger than the others."
The puppet pushed harder.
Perrin's eyes sharpened.
Weak Adapt Body.
His muscles adjusted.
His stance changed.
Not enough to overpower it.
Enough to redirect it.
Perrin shifted his blade.
The puppet's weapon slid off his Nichirin sword.
He stepped inside.
One slash.
Two.
Three.
He cut the controlling threads.
The body fell.
Mother backed away.
"No..."
Perrin looked at her.
White hair.
Red markings.
Fear.
She wasn't looking at Perrin anymore.
She was looking deeper into the mountain.
"No, no, no..."
Perrin frowned.
Mother grabbed her head.
"If I fail again..."
Perrin already knew who she was afraid of.
"Rui."
Her eyes snapped toward him.
"You know Rui?"
Perrin didn't answer.
Mother's expression twisted.
"I have to kill you."
Threads exploded from her fingers.
"If I don't..."
Perrin moved.
"...he'll kill me!"
Perrin slipped beneath the first thread.
Cut the second.
Parried another.
Mother continued backing away.
"I'M HIS MOTHER!"
Her voice cracked.
"I'M SUPPOSED TO PROTECT HIM!"
Perrin appeared in front of her.
"No."
Her eyes widened.
"You're terrified of him."
His sword moved.
DEATH BREATHING: FIRST FORM — TOUCH OF DECAY.
One clean strike.
Mother's head separated from her body.
Her expression changed.
Not anger.
Not hatred.
Relief.
Her body began breaking apart.
Perrin lowered his sword.
"...Yeah."
He looked away.
"That's what I remembered."
DANG!
Demon eliminated.
+1% Pezo Template Progress
Current Template Progress: 46%
Perrin stared at the fading ash.
Then at the timer.
06:51:03
"One."
He moved.
Spiders dropped from the branches.
Perrin immediately jumped backward.
One landed where his foot had been.
Another lunged.
He cut it apart.
Something hissed above him.
"Human."
Perrin looked up.
A grotesque figure clung to a web stretched between two trees.
Human head.
Spider-like lower body.
Perrin sighed.
"Elder Brother."
The demon's expression changed.
"You know me?"
"Enough."
More spiders crawled around Perrin.
Brother grinned.
"Then you know what happens when my spiders bite you."
Perrin looked around.
"Yeah."
Brother opened his mouth.
"Then become one of us."
Poison sprayed downward.
Perrin vanished from the spot.
The poison struck the ground.
Smoke rose.
Brother's smile disappeared.
"What?"
Perrin came from the side.
Brother twisted.
Too late.
DEATH BREATHING: FOURTH FORM — RESTLESS SHADE!
Perrin's movement broke into irregular angles.
Left.
Right.
Behind.
Forward.
Not teleportation.
Footwork.
Changes in rhythm.
Every time Brother adjusted, Perrin changed direction again.
One slash removed two spider legs.
Another opened his shoulder.
"STOP MOVING!"
Poison flew again.
Perrin ducked.
Brother lunged.
Perrin stepped past him.
The Nichirin Blade flashed.
Brother's head fell.
His body crashed into the dirt.
"...Impossible."
Perrin flicked blood from the blade.
"Not really."
The demon turned to ash.
DANG!
Demon eliminated.
+1% Pezo Template Progress
Current Template Progress: 47%
Perrin checked the timer.
05:58:11
"Two."
He looked toward the upper mountain.
"Now Rui."
The webs became thicker.
Perrin stopped several times just to study them.
Some crossed directly in front of him.
Others disappeared in the darkness.
Too many.
He stepped over one.
And Rui's are different.
Mother controlled with threads.
Brother relied on poison and spiders.
Rui's threads?
They killed.
That was it.
Simple.
Sharp.
Fast.
Strong enough to cut flesh apart before most people even understood what had touched them.
Perrin continued.
Then a voice came from ahead.
"Mother is dead."
Perrin stopped.
A pale boy stood between the trees.
White clothing.
Light hair.
Red markings.
Pale blue eyes.
The symbol in his left eye confirmed what Perrin already knew.
Lower Rank Five.
Rui.
"And Brother is dead."
Perrin slowly drew his sword.
Rui stared at him.
His expression barely changed.
"They failed."
Perrin said nothing.
"A mother protects her children."
Thin threads emerged from Rui's fingertips.
"An older brother protects his younger brother."
The threads spread between the trees.
"They couldn't even do that."
Perrin lowered his stance.
"That's not a family."
Silence.
Rui's eyes changed.
Perrin immediately regretted saying it.
Not because he disagreed.
Because he remembered what happened when Tanjiro challenged Rui's idea of family.
Rui lifted one finger.
"Don't say that again."
Perrin tightened his grip.
"Fine."
He breathed in.
"I'll just kill you instead."
The thread moved.
Perrin barely saw it.
His instincts screamed.
He ducked.
SHRRK!
Three trees behind him separated at once.
Perrin stared for half a second.
Rui's finger moved again.
Perrin jumped.
Threads crossed beneath him.
He landed.
More were already coming.
Fast.
Perrin blocked one.
CLANG!
His eyes widened.
The impact threw his sword aside.
A thin notch appeared along the edge.
Perrin jumped backward.
"...No."
Rui watched him.
Perrin looked at the blade.
His pulse increased.
I knew his threads could damage Nichirin.
But that force...
Another thread came.
Perrin dodged.
Something's off.
Rui tilted his head.
"You've killed two members of my family."
Threads spread around Perrin.
"You should replace them."
Perrin blinked.
"...Excuse me?"
"If you're strong enough."
Rui raised his hand.
"You could become my older brother."
Perrin stared at him.
"Hard pass."
Rui's face went blank.
Threads closed in.
Perrin inhaled sharply.
DEATH BREATHING: THIRD FORM — GRIM FINALE!
Perrin exploded forward.
His blade swept through three threads.
SNAP!
Four.
Five.
The sixth caught the sword.
Perrin forced through it.
Rui's eyes widened slightly.
Perrin reached his neck.
Got you.
His sword swung.
A thread flashed.
Rui's head separated.
Perrin's blade passed through—
air.
He landed.
Rui's head fell.
Perrin didn't relax.
"Nice try."
Rui's head stared at him.
Perrin remembered this.
Rui had cut through his own neck before Tanjiro's blade could finish the decapitation.
A demon wasn't killed just because its head came off.
The Nichirin Blade had to do it.
Threads pulled Rui's head back toward his body.
Perrin moved immediately.
"Not twice."
His blade came down.
Blood-red threads erupted.
CLANG!
Perrin was thrown backward.
His feet hit the ground.
He slid nearly twenty feet.
When he looked up—
Rui's threads had changed.
Red.
Blood infused.
Perrin swallowed.
"Okay."
Rui's head reattached.
His expression wasn't calm anymore.
"You nearly broke my bond."
Blood-red threads spread everywhere.
Perrin's pupils tightened.
This is where it gets serious.
Rui brought his hands together.
Threads formed around Perrin.
Above.
Behind.
Both sides.
A cage.
Perrin recognized it.
"Cutting Thread Cage."
Rui's fingers closed.
The web contracted.
Perrin swung.
CLANG!
One thread deflected the blade.
Another cut his shoulder.
Blood sprayed.
"Gh!"
Perrin twisted away.
A second thread opened his leg.
His breathing sharpened.
Weak Adapt Body.
The skill activated harder.
Thread movement.
Tension.
Angles.
Rui's fingers.
The direction they pulled.
Perrin's eyes moved constantly.
Learn.
A thread passed his cheek.
Faster.
Another came from behind.
Perrin bent under it.
Learn.
The cage tightened.
His stamina dropped.
His body began adjusting to the movement pattern.
Not the cutting power itself.
Not enough.
But the timing.
Perrin found one opening.
"Death Breathing..."
He brought his sword back.
"Fourth Form—"
He vanished through the smallest gap.
RESTLESS SHADE!
The cage snapped shut behind him.
Trees shredded apart.
Perrin landed.
Rui stared.
Perrin breathed heavily.
"...That would've killed me."
Rui raised both hands.
"So?"
More threads formed.
Perrin's smile disappeared.
Rui's blood-red threads began rotating.
Perrin remembered that technique too.
And when he had seen it used.
His stomach tightened.
"Already?"
BLOOD DEMON ART — CUTTING THREAD ROTATION.
A storm of crimson threads tore toward him.
Perrin moved.
One cut across his ribs.
Another tore through his sleeve.
A third nearly took his arm.
Perrin blocked.
CRACK!
The Nichirin Blade screamed against the threads.
"Come on..."
His arms shook.
"COME ON!"
The sword held.
Barely.
Perrin forced himself sideways.
The rotating threads passed.
Everything behind him came apart.
Perrin looked at the destruction.
Then at Rui.
No.
His chest rose and fell.
This is wrong.
Not Rui's techniques.
Those he remembered.
The problem was how much power sat behind them.
The pressure.
The speed.
How quickly Rui escalated.
Perrin tightened his grip.
Think later.
Rui moved his hands again.
Survive now.
Perrin rushed him.
Rui sent threads directly at his neck.
Perrin ducked.
Shoulder.
Dodge.
Stomach.
Turn.
Leg.
Jump.
Weak Adapt Body burned through his stamina.
But Perrin was learning Rui.
Not perfectly.
Enough.
Rui pulled his right hand inward before changing the angle of the red threads.
Perrin saw it.
There.
He moved first.
Rui's eyes widened.
Perrin crossed inside the thread pattern.
"Death Breathing..."
His entire body tightened.
Every muscle.
Every breath.
One strike.
No wasted movement.
FIFTH FORM — MOURNING DAWN!
Rui threw every nearby thread toward him.
Perrin didn't stop.
He cut one.
Two.
Three.
The fourth sliced into his arm.
Perrin continued.
The fifth opened his side.
Still moving.
Rui raised a thread toward his own neck.
Perrin saw it.
"Not this time."
He changed the angle of his blade.
Instead of Rui's neck—
Perrin cut the self-decapitation thread first.
SNAP!
Rui's eyes widened.
"What—"
Perrin completed the swing.
The Nichirin Blade passed cleanly through Rui's neck.
Silence.
Rui's head fell.
This time—
the cut belonged to Perrin.
Rui's body remained standing for a moment.
His fingers twitched.
The threads disappeared.
The body collapsed.
Rui stared upward from the ground.
His face wasn't shocked anymore.
Just confused.
"...Family..."
Perrin didn't answer.
Ash began spreading across Rui's face.
"...I..."
His voice disappeared.
The Lower Rank crumbled.
Wind carried the ash through the trees.
Perrin stood motionless.
Then—
DANG!MISSION COMPLETERUI — LOWER RANK FIVE ELIMINATED
Pezo (Human) Template Progress: +5%
Current Template Progress: 52%
Perrin's eyes widened slightly as power rushed through him.
Muscles tightened.
His senses sharpened.
The exhaustion didn't disappear.
If anything, now that the fight was over, his body seemed to remember every wound simultaneously.
"Ow."
His knee hit the ground.
"Yeah..."
He breathed.
"Definitely feeling that."
Another sound rang through his head.
DANG!BONUS REWARD GENERATEDDEEP ONES SKILL ACQUIREDABYSSAL IDENTIFICATION
LV. 1 — 0/100
Description
Distance has no meaning to the Abyss once an identity is sufficiently understood.
By learning, observing, and understanding a specific individual, the user establishes an Abyssal Identification with that target.
Once identification reaches the required threshold, the user may cross the distance separating them.
CORE LAW
When you know someone enough, you can cross any distance.
Physical distance does not determine success.
Identification does.
A name alone is insufficient.
Perrin forgot about the pain for approximately three seconds.
"...What?"
He reread it.
Then again.
"Abyssal..."
His eyes stopped on the core law.
"...Identification."
Perrin slowly stood.
"So if I know somebody well enough..."
He looked toward the fading remains of Rui.
"...distance doesn't matter?"
The System offered no further explanation.
Perrin stared at the screen.
"That's horrifying."
The screen vanished.
"...Useful."
He sheathed the damaged Nichirin Blade.
"Still horrifying."
Perrin started walking down the mountain.
He made it twenty steps.
Stopped.
His expression slowly changed.
The fight replayed inside his head.
Rui's first thread.
The force.
The speed.
The blood-red threads.
How quickly Perrin had been forced to use Weak Adapt Body seriously.
How close Cutting Thread Cage had come to turning him into pieces.
Perrin looked back.
Only ash remained.
"...Wait."
Silence.
Perrin's eyes narrowed.
"Rui was too strong."
He knew Rui was dangerous.
He remembered that.
He remembered Tanjiro being overwhelmed.
He remembered Rui's threads being capable of cutting a Nichirin Blade.
He remembered the Blood Demon Art.
That wasn't the problem.
Perrin touched the cut across his ribs.
"The difference was too big."
His breathing slowed.
"And I barely changed anything."
He had hunted demons.
Trained.
Survived.
But he hadn't gone around tearing apart the main story.
He hadn't spent years hunting Twelve Kizuki.
He hadn't interfered with Muzan.
He hadn't done anything that should have caused Rui to become noticeably more dangerous than the Rui he remembered.
Perrin stared deeper into Mount Natagumo.
"...So it isn't me."
A cold feeling settled into his stomach.
"Something else is messing with the plot."
His hand rested on the hilt of his Nichirin Blade.
For the first time since arriving in this world, Perrin's memories of Demon Slayer didn't feel like an advantage.
They felt outdated.
Perrin turned away from the mountain.
"...Great."
He started walking.
"Because apparently reincarnating into Demon Slayer wasn't bad enough."
Behind him, Rui's final ashes vanished into the night.
And Perrin didn't look back.