The grotesque demon—
Captured during the Edo period by the former Water Hashira, Urokodaki, and sealed within the Final Selection grounds.
It survived.
Ate over fifty people.
Driven by hatred toward the man who captured it—
It targeted those wearing fox masks carved by Urokodaki.
It trusted in the toughness of its neck.
And within Mount Fujikasane—
It was one of the most vicious, most dangerous demons.
Night.
Dust filled the air.
A flash of lightning severed its arms.
Someone caught the unconscious Kuroba and leapt back.
"…Hm?"
The demon froze, confused.
All it sensed—
It was lightning.
And a strange scent.
Not human blood.
I looked forward to it.
The lightning faded.
A girl in a crimson haori stood there, blade lowered—
Its edge gleaming gold.
Nearby, Sanemi gently set Kuroba down, his face twisted.
"Didn't expect trash like you hiding here."
"Oh?" the demon sneered.
"Another Thunder Breather?"
Its arms had already regenerated.
"What year is it now, huh?"
Sui didn't answer.
Her gaze fell on a bloodstained Nichirin blade on the ground.
She could hear it—
The echo of thunder.
Its owner had used the same breathing.
"Damn it—I'll kill you!"
Sanemi stepped forward—
But Sui's slender arm stopped him.
"Stand down."
Her tone—
Calm.
Absolute.
And for once—
Sanemi obeyed.
"…Tch."
He stepped back.
"Who helped you hide here?" Sui asked.
"The hell are you talking about?" the demon snarled.
"And answer me—what year is this?!"
Sui moved.
A single swing—
All its arms were severed before it could react.
Blood mist exploded outward.
"You brat—!"
It roared.
The arms regenerated—
Merged—
Then shot forward like a cannon.
Sui cut through them again.
Effortlessly.
Cleanly.
"Demon Slayers regularly sweep this mountain," she said, stepping forward.
"No demon survives this long unnoticed."
Before it could react—
She pressed her blade against its forehead—
Severing the arms shielding its neck.
"AAAGH—! IT HURTS!"
Its voice trembled.
For the first time—
Fear.
Because the woman before it—
Overlapped with a memory.
A Hashira.
Cold.
Unreachable.
Terrifying.
And she wasn't even using a breathing form.
"…Who?" she asked again.
"I DON'T KNOW WHAT YOU'RE TALKING ABOUT!"
Lightning erupted.
Not to kill—
But to consume.
Dark violet arcs crawled over its body—
Eating it alive.
But never cutting the neck.
Time passed.
From night—
To dawn.
The demon regenerated endlessly—
Only to be torn apart again.
Its strength became its torment.
The smell—
Burnt flesh and rot—
It was unbearable.
Sanemi grinned.
"Yeah… that's it."
"Killing it is too easy."
"This is better."
He was already thinking about how to replicate it with Wind Breathing.
Sui stopped.
Not because she got answers—
But because the sun rose.
Light touched the broken body.
It burned.
Turned to ash.
After all that—
It couldn't even scream.
Sui took out a sachet—
Then paused.
Mist rose.
Behind where the demon had been—
A scene appeared.
A large stone.
A boy with flesh-colored hair, wearing a fox mask, sitting on it.
In front of him—
A smaller girl.
Even younger than Kuroba.
Around them—
More figures.
All wearing fox masks.
Watching her.
"…What is this?"
Sui opened her eyes.
Blue light shimmered—
Her Mystic Eyes activated.
But—
There were no lines.
No death.
Like a blank canvas.
The boy jumped down.
The small girl waved.
A farewell.
Then—
They vanished into the mist.
The smell of rot returned.
Reality snapped back.
"…Still nothing?" Sanemi said.
"That thing didn't talk?"
Sui closed her eyes.
"…Maybe it really didn't know anything."
"Just a demon driven by revenge."
"No way," Sanemi snapped.
"That thing didn't survive here by accident."
"Excuse me…"
A weak voice.
Kuroba had awakened.
She looked at Sui—
Grateful.
But her eyes—
Dim.
"Don't move, idiot!" Sanemi barked.
She smiled faintly.
"Thank you… both of you…"
"I'll tell my master… the nightmare is finally over…"
Sanemi crossed his arms, looking away.
Sui knelt beside her, gently touching her forehead.
"Turn around, Sanemi."
"…What now?"
Sui smiled slightly.
"I need to treat her wounds."
"Or do you enjoy watching girls undress?"
"…You—!"
Sanemi left instantly.
Sui examined her injuries.
"Your right arm is shattered."
"Internal damage is severe."
In other words—
She could never fight again.
But Kuroba just smiled.
"…You're beautiful."
"I'm Sui. He's Sanemi. Don't mind him—he's actually kind."
She redressed her wounds carefully.
"There's no proper treatment here."
"I'll arrange for you to leave."
"No."
Kuroba shook her head.
"If I survive seven days… I passed."
"I won't give up."
"It's my wish… and my master's."
Sui paused.
Every Demon Slayer had a story.
Most of them are heavy.
"…Alright."
She handed over food.
"There are no demons left here now."
"Endure five more days."
"You'll live."
"What about you?"
"I'll hunt."
"There are plenty of rabbits."
Sui smiled, patting her head.
"Goodbye."
Later—
Sanemi sat in a clearing.
Roasting rabbits over a fire.
Fat dripped.
The smell was rich.
"Yo! Two are yours!"
He tossed one over.
Sui sniffed lightly.
"…Rabbits are cute."
Sanemi frowned.
He knew that tone.
Here it comes.
"…So?"
"They should all be mine."
"…Of course."
He wasn't even surprised.
He tried to grab them—
Too slow.
Lightning flickered.
"HEY! OI! GIVE THAT BACK!"
"Two! I said two is fine!"
"ONE! JUST LEAVE ME ONE!"
"DAMN IT!"