They had not stopped moving for twenty-three minutes.
No one spoke.
Words felt dangerous now—like speaking too loudly might remind the Abyss they were still alive.
Only the sound of boots scraping over black stone and controlled breathing disturbed the silence.
Even that felt wrong.
Every step echoed less than it should have.
As if the ground beneath them refused to acknowledge their existence.
The Abyss stretched endlessly around them.
Unchanging.
Unnatural.
No landmarks.
No variation.
No proof they had progressed at all.
Just the same endless dark corridor of warped stone and suffocating stillness.
Yuna's hand tightened around her weapon.
"…How long has it been since we last heard him?"
No one answered.
Because no one wanted to admit it.
They had not heard him once.
Not footsteps.
Not breathing.
Not pursuit.
And somehow—
That was worse.
Fushimi suddenly froze.
His entire body locked.
His voice emerged as barely more than air.
"…Behind us."
Everyone turned instantly.
Weapons raised.
Aether surged.
Nothing.
Only darkness.
Yuna's breathing quickened.
"…I don't see anything."
Kurose narrowed his eyes.
Neither did he.
But something was there.
Because thirty meters behind them—
A fresh line had appeared on the wall.
Clean.
Perfect.
Still smoking.
Kanzaki's face paled.
"…That mark wasn't there."
Silence.
Then—
Another line carved itself beside the first.
No visible blade.
No visible hand.
Just—
SCRAPE.
Stone split open.
A second mark.
Longer.
Deeper.
More precise.
Yuna stepped back.
"…He's doing that now?"
A third line appeared.
Closer.
Then a fourth—
Directly beside them.
Everyone flinched.
Kurose's expression hardened.
"No."
His voice dropped low.
"…He's showing us."
A cold realization passed through the group.
He wasn't hiding.
He wasn't stalking.
He was making sure they knew—
He was always close enough to kill them.
The air shifted.
Subtly.
Like reality itself had inhaled.
And then—
He was there.
Standing ten meters ahead.
No footsteps.
No sound.
No transition.
Just—
Present.
Ryuzen.
Pale skin smooth as carved marble.
Black veins faint beneath the surface.
Gray-stained fingertips.
Eyes empty—
But not mindless.
Watching.
Learning.
His head tilted slightly.
Studying them with the detached curiosity of something dissecting prey before deciding where to cut.
Yuna's voice trembled.
"…Ryuzen…"
The name echoed softly into the dark.
Something flickered in his eyes.
His body twitched.
Once.
Sharp.
Violent.
Then stopped.
Everyone saw it.
Kanzaki whispered—
"…He reacted."
For one second—
Hope entered the silence.
Then died.
Ryuzen raised his hand.
Gray-black flame formed in his palm.
Unstable.
Violent.
It twisted like something alive—
Then collapsed inward.
He stared at it.
As if irritated.
As if something had failed.
Kurose's gaze sharpened.
"…He's still incomplete."
No one understood.
Until—
He moved.
Aether exploded around Kurose.
Light erupted into existence behind him—
Six radiant lances materialized in the air.
Each humming with compressed force.
Each capable of obliterating high-tier monsters.
The air bent under their pressure.
Yuna's eyes widened.
"…Captain—"
"Now."
The lances fired.
They screamed through the Abyss.
Ryuzen's eyes tracked them.
His stolen scanner-light flickered faintly across his pupils.
『 ANALYSIS: KINETIC LIGHT STRUCTURE 』
『 PARTIAL INTERPRETATION 』
He raised one hand.
The first lance struck—
And shattered.
The second twisted off course.
The third bent—
Then froze.
Gray spread across its surface.
Only one.
Just one.
It reversed.
Flying back—
Faster.
Harder.
Kurose barely reacted.
His barrier flared—
Then exploded.
The impact launched him backward across the stone.
He skidded violently.
Blood ran from his lip.
But his eyes sharpened instead of widening.
"…Partial adaptation."
Kanzaki stared.
"…He couldn't rewrite all of them…"
Her voice dropped.
"…Yet."
Yuna moved.
Instinctively.
Too fast.
Too emotional.
She rushed his blind side—
Fushimi flanking opposite.
A coordinated pincer.
Perfect textbook execution.
Ryuzen didn't even look at them.
He simply shifted.
Once.
A broken flicker.
Their attacks struck empty air.
He was suddenly behind them.
Neither had seen him move.
Yuna's breath caught—
"He's—!"
Ryuzen's hand shot toward her throat.
Fushimi intercepted instantly.
Steel met flesh.
CLANG.
Sparks erupted.
His blade cut—
Slightly.
A thin gray line appeared across Ryuzen's forearm.
Everyone froze.
Even Ryuzen.
He looked down.
At the wound.
At the gray blood slowly leaking from it.
His fingers touched it.
He stared.
Processing.
Then—
His eyes shifted to Fushimi.
Focused.
Interested.
Fushimi's breathing faltered.
"…Captain…"
Ryuzen moved.
Faster than before.
His palm struck Fushimi's chest—
Not hard.
Not wild.
Precise.
The impact launched him backward.
Bones cracked.
He hit the wall with sickening force and collapsed.
"FUSHIMI!"
Yuna rushed toward him—
Kurose caught her wrist.
"DON'T."
Ryuzen stood still again.
Looking at the wound.
Watching it close.
Gray flesh knitting itself together.
Slowly.
Learning.
Adapting.
Then—
His lips moved.
A sound emerged.
Broken.
Layered.
As if several voices were trying to use one throat.
"…Fu…shi…"
Silence.
Everyone froze.
Kanzaki's eyes widened.
"…He's repeating names…"
Another twitch struck him.
Violent.
His body jerked unnaturally.
The flame in his hand burst outward—
Then imploded.
He grabbed his head.
Static crackled through the air.
His entire frame distorted.
Like something inside him was breaking apart.
Then—
He spoke again.
Clearer.
More human.
"…Ru…"
His eyes widened slightly.
Like something deep inside had recognized itself.
And then—
Memory.
A flash.
Warm firelight against cold night air.
Rain tapping softly against canvas.
Voices.
Laughter.
Someone shoving his shoulder.
A girl's voice saying—
"You're impossible, Ryuzen."
Another memory—
Classroom windows streaked with rain.
A desk.
A notebook.
Hands stained with ink.
A smile—
Then—
BLACK STATIC.
The memory shattered.
Corrupted.
Burned away.
Ryuzen staggered.
The Abyss pulsed with him.
Walls bent inward.
Ground cracked.
The stone beneath their feet groaned like a living thing.
Kanzaki shouted—
"His memory's destabilizing the layer!"
Ryuzen let out a sound—
Half scream.
Half static.
He clawed at his own face.
Gray blood dripped through his fingers.
Fragments of broken words escaped him—
"…wh…o…"
"…why…"
"…hurts…"
Yuna stared.
Her voice cracked.
"…He's suffering…"
Kurose's face hardened.
"Move!"
They reacted instantly.
Fushimi was hauled up between them.
The team retreated.
Fast.
Desperate.
No one looked back.
Not until the pressure lessened.
Not until distance returned.
Only then—
Yuna turned.
Far behind—
Ryuzen stood motionless.
Still clutching his head.
Still trembling.
His voice echoed faintly through the dark.
Small.
Broken.
Almost human.
"…Ry…u…zen…"
Then silence.
Absolute.
No one spoke for several seconds.
Only ragged breathing remained.
Yuna's hands trembled.
"…Captain…"
Kurose stared into the darkness.
His face pale.
His jaw tight.
He answered without looking away.
"…That thing remembers."
Kanzaki swallowed hard.
"…Then maybe there's still—"
"No."
Kurose cut her off instantly.
Cold.
Sharp.
"That is not your friend."
Yuna flinched.
"But—"
"It remembered a name."
His voice lowered.
"That does not mean it remembered being human."
Silence.
Kanzaki adjusted her broken glasses with trembling fingers.
"…Then what do you think happened?"
Kurose finally looked at them.
And for the first time—
His calm looked forced.
"…I think something in there is wearing his memories like broken armor."
No one had an answer to that.
Because no one wanted to believe it.
Yet no one could deny what they had seen.
A monster had spoken his own name—
And sounded like it hurt.
Far behind them—
Deep within the breathing dark—
Ryuzen slowly lowered his hand.
His eyes were empty again.
But his lips moved once more.
Quietly.
Testing the shape of the word.
"…Ry…uzen…"
He looked at his reflection in a pool of black ichor.
The face staring back at him was his.
Mostly.
But the eyes—
Were not.
He touched the surface.
Ripples spread.
And in the reflection—
For a split second—
The thing beneath his skin smiled.
Wide.
Jagged.
Wrong.
Ryuzen's head tilted.
As if confused.
As if disturbed.
Then he took one step forward.
Toward where they had fled.
Not chasing.
Not hunting.
Following.
Because somewhere beneath the static—
Some buried fragment of him wanted to know—
Why that name
felt like pain.
[ END OF CHAPTER 4 ]