Volume 1: The Fourth Holy Grail War
Chapter 1: The Beginning Beyond Fate (Part I)
The first thing Ren felt was the biting cold.
It wasn’t the comfortable chill of an air-conditioned room, nor the refreshing breeze of a winter morning.
It was a damp, suffocating cold that seeped into his bones.
“…”
His eyelids fluttered open.
A dim alley stretched before him, illuminated only by the weak glow of a distant streetlamp.
Rainwater slowly trickled through cracked concrete, carrying bits of trash toward a rusted drainage grate.
The faint smell of iron lingered in the air.
Ren frowned.
“…Where…”
His voice echoed softly.
He instinctively reached for his pocket.
No phone.
No wallet.
No keys.
Nothing.
His breathing became uneven.
“I…
wasn’t I at home?”
His memories were clear.
He had been reading late into the night before deciding to sleep.
Nothing unusual.
Nothing dangerous.
Yet now…
He slowly stood, steadying himself against the cold brick wall.
The alley was unfamiliar.
The buildings were unfamiliar.
Even the sky looked…
Different.
Dark clouds drifted above a city illuminated by orange streetlights.
Far in the distance, church bells quietly rang.
“…”
Ren stepped out of the alley.
The street before him was strangely peaceful.
Cars passed by.
People walked home.
A convenience store stood across the road.
Everything appeared perfectly normal.
Except…
None of it felt familiar.
He glanced toward a nearby traffic sign.
The language.
Japanese.
“I can read it…”
That realization surprised him.
He had studied some Japanese before, but nowhere near enough to read it fluently.
Yet every word made perfect sense.
“…What is going on?”
A dull ache spread through his head.
Then—
A voice.
Not spoken.
Not heard.
It simply appeared inside his consciousness.
══════════════════════════════
Initializing…
Synchronization…
0%
══════════════════════════════
Ren froze.
“…”
“…A hallucination?”
The translucent interface floated before his eyes.
Pedestrians walked past him without the slightest reaction.
They couldn’t see it.
══════════════════════════════
Synchronization…
12%
World Recognition…
Complete.
══════════════════════════════
“…”
His heartbeat accelerated.
He rubbed his eyes.
The interface remained.
“…No way…”
══════════════════════════════
Synchronization…
46%
══════════════════════════════
The percentage climbed steadily.
Ren forced himself to calm down.
Panic wouldn’t help.
He needed information.
His eyes wandered across the street.
The architecture…
The vehicles…
The advertisements…
Everything looked unmistakably Japanese.
Then his gaze stopped.
Across the road stood a blue road sign.
Fuyuki City
“…”
Silence.
“…Fuyuki?”
His pupils contracted.
“…No…”
“No…”
“That can’t be…”
Fuyuki City.
There was only one place he knew by that name.
The city where the Fourth and Fifth Holy Grail Wars took place.
The city where Heroic Spirits clashed.
The city where countless innocent people died.
His breathing became shallow.
“…This is impossible.”
══════════════════════════════
Synchronization…
100%
══════════════════════════════
The interface vanished.
For a brief moment…
Nothing happened.
Then another screen quietly appeared.
══════════════════════════════
Astra Horizon
World Synchronization
Complete.
══════════════════════════════
“…”
A new message followed immediately.
══════════════════════════════
Identity Established.
Residence Established.
Financial Records Established.
Communication Access Established.
Language Synchronization Complete.
World Integration Successful.
Welcome,
Ren Aoki.
══════════════════════════════
“…”
Ren stared blankly.
“…Ren…”
“…Aoki…”
The name felt…
Natural.
As though it had always belonged to him.
Memories that weren’t entirely his own surfaced.
An apartment.
A bank account.
A school transcript.
A driver’s license.
None of those memories existed a minute ago.
Yet now…
He knew exactly where his apartment was.
He knew the PIN to his bank card.
He even knew the route home.
“…”
“This…”
“This is insane.”
The interface faded once more.
Only one word remained in his thoughts.
Status.
The moment the thought crossed his mind—
══════════════════════════════
Astra Horizon
Status Sheet
Name
Ren Aoki
Alias
Ren
Race
Human
Alignment
Neutral Good
Current World
Nasuverse
World Record
Nasuverse
└── Fate/Zero Timeline [Current]
Parameters
Strength
E
Endurance
E
Agility
D
Mana
E
Luck
EX
Personal Skills
Noble Phantasms
══════════════════════════════
“…”
Ren remained silent for a long moment.
He wasn’t dreaming.
The interface responded instantly to his thoughts.
He tried another command.
Inventory.
Another screen appeared.
══════════════════════════════
Inventory
Items
• Apartment Key
• Smartphone
• Wallet
• Identification Documents
• Bank Card
• ¥50,000 Cash
══════════════════════════════
His hand instinctively reached into his pocket.
A wallet.
Exactly as listed.
Opening it revealed neatly organized bills.
His identification card.
A debit card.
Everything looked perfectly genuine.
“…”
He laughed softly.
Not because it was funny.
Because reality had become absurd.
He had been dropped into the world of Fate.
And somehow…
Something called Astra Horizon had already prepared a place for him.
A home.
A name.
An existence.
No questions asked.
The cold evening wind swept through the street.
Ren slowly closed his wallet.
His expression gradually became serious.
“…If this really is Fate/Zero…”
His mind immediately raced through everything he remembered.
Kiritsugu Emiya.
Kirei Kotomine.
Gilgamesh.
Iskandar.
Lancer.
Saber.
Caster.
Then…
One name emerged above all others.
“…Ryuunosuke Uryuu.”
Ren’s eyes narrowed.
“If I remember correctly…”
“He hasn’t summoned Caster yet.”
That meant…
The Holy Grail War had not truly begun.
History…
Could still be changed.
The thought had barely formed when Astra Horizon quietly responded.
══════════════════════════════
Mission Detected.
Potential Point of Divergence Identified.
View Mission?
YES / NO
══════════════════════════════
Ren looked at the glowing prompt.
Without hesitation—
He chose YES.
Volume 1: The Fourth Holy Grail War
Chapter 1: The Beginning Beyond Fate (Part II)
Ren silently stared at the translucent interface floating before him.
The words remained unchanged.
══════════════════════════════
Mission Detected.
Potential Point of Divergence Identified.
View Mission?
YES / NO
══════════════════════════════
“…”
Taking a slow breath, Ren mentally selected YES.
The interface immediately dissolved before reorganizing itself.
══════════════════════════════
Mission
Prevent the summoning of the Heroic Spirit
‘Caster.’
Target
Ryuunosuke Uryuu
Mission Description
Eliminate or prevent the target
from successfully completing the
summoning ritual.
Mission Status
Available
Reward
???
══════════════════════════════
There was no mention of failure.
No countdown.
No punishment.
“…So it really doesn’t force me.”
Ren nodded slightly.
That suited him better.
Astra Horizon merely pointed out opportunities.
Whether to seize them…
Was entirely his decision.
“…”
Unfortunately—
There wasn’t much to think about.
If there was one person Ren would never hesitate to remove from history…
It was Ryuunosuke Uryuu.
A serial killer.
A child murderer.
A monster wearing human skin.
If Caster was never summoned…
Hundreds of innocent lives would be saved.
The horrifying river monster.
The countless sacrifices.
Those tragedies would simply…
Never happen.
“…”
Ren closed the Mission window.
The streets bustled with evening traffic.
To everyone else, it was another ordinary day.
Nobody realized that within the next few days…
Seven Heroic Spirits would descend upon Fuyuki.
A war older than most nations would begin.
“…First things first.”
He needed information.
Nearly thirty minutes later.
Ren sat inside a small café overlooking one of Fuyuki’s main streets.
A steaming cup of coffee rested before him.
His smartphone lay beside it.
It looked completely ordinary.
Turning it on revealed nothing unusual.
Contacts.
Messages.
Maps.
Internet.
Everything functioned perfectly.
“…”
He opened a search engine.
Fuyuki City Murders
Several articles appeared.
Most described a string of bizarre disappearances.
Children.
Families.
Unidentified bodies.
Police investigations with no leads.
“…”
Just as I remembered.
Ryuunosuke had already begun killing.
He simply hadn’t obtained the catalyst necessary to summon Gilles de Rais.
That meant…
There was still time.
Ren leaned back.
“…”
His greatest advantage wasn’t Astra Horizon.
Not yet.
It was knowledge.
Knowledge of events that had yet to occur.
Knowledge no one else possessed.
“…”
That advantage would disappear quickly once the timeline began changing.
Meaning—
Every decision mattered.
Leaving the café, Ren followed the memories Astra Horizon had integrated into his identity.
The apartment wasn’t luxurious.
A modest one-bedroom residence near the edge of the city.
Clean.
Organized.
Fully furnished.
Exactly enough for one person.
“…”
Placing the key into the lock…
Click.
The door opened.
A quiet room greeted him.
Bookshelves.
A television.
Kitchen.
Bedroom.
Bathroom.
Everything appeared lived in.
Not staged.
Someone looking into his records would find years of rental payments.
Utility bills.
Tax records.
Everything.
“…Impressive.”
Ren couldn’t help but admire Astra Horizon.
It hadn’t merely given him an identity.
It had woven his existence into the fabric of this world.
As though he had always belonged here.
Inside the apartment…
Ren immediately began writing.
Not a diary.
A timeline.
Every major event he could remember.
Fourth Holy Grail War.
Master pairings.
Locations.
Known Noble Phantasms.
Hidden identities.
Possible outcomes.
“…”
Hours passed.
Sheets of paper gradually covered the table.
Finally…
Ren leaned back.
“…Not perfect.”
“But enough.”
Memories faded with time.
He couldn’t remember every detail.
However…
The major turning points remained clear.
Caster.
The docks.
The Einzbern Castle.
The river battle.
Kiritsugu’s final confrontation.
The Great Fire.
“…”
Then…
One detail suddenly caught his attention.
“…Wait.”
He frowned.
“If Ryuunosuke dies…”
Caster never appears.
Which means…
Several battles never happen.
Saber conserves magical energy.
Lancer survives longer.
Kiritsugu’s strategies change.
Even Kirei’s movements could change.
“…”
It wasn’t just one event.
It was an entire chain reaction.
“…”
His heartbeat quickened.
That was exactly what Astra Horizon sought.
Not simply changing events.
Changing Fate itself.
Ren stood.
There was no point delaying.
Every passing hour increased the chance that Ryuunosuke would complete the summoning ritual.
“…Inventory.”
The interface appeared.
══════════════════════════════
Inventory
• Apartment Key
• Smartphone
• Wallet
• Identification Documents
• Bank Card
• ¥7,950,000
• ¥50,000 Cash
══════════════════════════════
“…”
His eyebrows rose slightly.
Apparently the fifty thousand yen was merely the cash he carried.
The remainder remained safely inside his account.
More than enough to support himself for quite some time.
“…Good.”
Money…
Wouldn’t become a concern.
Night had already fallen.
Streetlights illuminated the roads.
Ren walked alone beneath the silent sky.
No fear.
No hesitation.
Only determination.
“…”
“I know what kind of person he is.”
“A monster like him…”
“…deserves no mercy.”
He wasn’t a hero.
Nor was he pretending to be one.
He simply refused to stand by while history repeated itself.
If he possessed the ability to stop it…
Then he would.
The cold wind blew once more.
Without warning—
Astra Horizon quietly appeared.
══════════════════════════════
Mission Update
Target located.
Distance
4.2 km
Navigation Authority
Temporarily Granted
══════════════════════════════
“…”
Ren blinked.
A faint golden line appeared only within his vision.
Beginning beneath his feet…
It stretched through the streets of Fuyuki…
Disappearing somewhere far ahead.
“…”
“So that’s how…”
Astra Horizon wasn’t giving him a permanent map.
It was simply guiding him toward the active mission.
Just enough assistance.
Nothing more.
Ren smiled faintly.
“…Convenient.”
Without another word…
He followed the golden path into the darkness.
Somewhere ahead…
A serial killer continued preparing the ritual that should have summoned one of history’s most infamous Heroic Spirits.
Tonight…
History would take its very first step away from its predetermined course.
And Fate…
Would begin to change.
Volume 1: The Fourth Holy Grail War
Chapter 1: The Beginning Beyond Fate (Part III)
The golden trail extended quietly before him.
Unlike the bright navigation systems from games, the path generated by Astra Horizon was subtle.
It resembled a faint stream of starlight, visible only to Ren, gently winding through the streets of Fuyuki.
The city had fallen into silence.
Most shops had already closed, while the occasional convenience store remained lit, serving the few late-night customers.
Ren walked at a steady pace.
His heartbeat had long since calmed.
Instead, his thoughts were occupied by a single question.
“How am I supposed to kill him?”
Ryuunosuke Uryuu wasn’t a magus.
He wasn’t even a trained fighter.
But Ren wasn’t one either.
His current Status Sheet reflected reality.
Strength: E.
Endurance: E.
He was simply an ordinary human.
One mistake…
Would be fatal.
“…”
As if sensing his concern, Astra Horizon responded.
══════════════════════════════
Mission Assistance
Host’s survival probability
against the target:
71.43%
Recommendation:
Utilize the surrounding
environment.
══════════════════════════════
“…”
“No more than that?”
The interface disappeared.
Ren couldn’t help but smile wryly.
“You’re really stingy.”
No answer came.
As always.
Nearly twenty minutes later…
The scenery gradually changed.
The residential district gave way to an abandoned industrial area near the outskirts of Fuyuki.
Old warehouses stood like forgotten giants beneath the moonlight.
Broken fences.
Rusted containers.
Cracked concrete.
The air smelled faintly of oil.
The golden trail finally came to a stop.
Ren immediately crouched behind a stack of weathered shipping pallets.
Ahead…
An abandoned slaughterhouse.
“…”
His expression hardened.
Even before entering…
He could smell it.
Blood.
Old blood.
A metallic odor that lingered in the air despite the passing days.
His stomach churned.
“…Damn…”
The information from Fate/Zero had never truly conveyed how horrifying this place was.
This wasn’t fiction anymore.
Somewhere inside…
There were real victims.
Real lives.
Taken by someone who viewed murder as entertainment.
Ren closed his eyes.
“No hesitation.”
“If I hesitate…”
“Someone else dies.”
Keeping low, he slowly approached one of the shattered windows.
The inside was dimly lit by several candles.
Scattered across the room were dozens of grotesque “artworks.”
Pieces of machinery.
Dissecting tables.
Medical instruments.
Children’s toys.
And…
Blood.
Far too much blood.
At the center of the room stood a young man humming happily to himself.
Messy orange hair.
A cheerful smile.
As if he were preparing for a birthday party.
Ryuunosuke Uryuu.
“…”
Ren felt a wave of disgust.
The man looked…
Normal.
Almost friendly.
Which somehow made him even more terrifying.
“…Perfect…”
Ryuunosuke picked up an old book from the table.
A worn leather tome.
Its pages seemed to move unnaturally beneath the candlelight.
Ren immediately recognized it.
“The Prelati’s Spellbook…”
“So he already has it…”
His gaze narrowed.
“No…”
Something wasn’t right.
The room lacked one crucial element.
There was no summoning circle.
Which meant…
“He hasn’t started yet.”
Good.
There was still time.
Ren quietly scanned the surroundings.
Near the entrance lay an iron pipe.
Heavy.
Solid.
He slowly picked it up.
The cold metal felt reassuring in his hands.
“…”
One strike.
That was all he needed.
If he failed…
There wouldn’t be a second chance.
Inside the slaughterhouse…
Ryuunosuke laughed to himself.
“Hmm?”
“I wonder what kind of funny things this book can do.”
He casually flipped another page.
Completely unaware.
Ren inhaled deeply.
One step.
Another.
Another.
The distance shortened.
Ten meters.
Eight.
Five.
Three—
The iron pipe swung downward with every ounce of strength Ren possessed.
CRACK!
The impact echoed through the empty building.
Ryuunosuke collapsed to one knee with a cry of pain.
“…Huh?”
He instinctively reached toward the back of his head.
His fingers came away stained red.
Blood.
“…”
He slowly turned around.
His cheerful smile remained.
“…Eh?”
“Who’re you?”
“…”
Ren didn’t answer.
He swung again.
Ryuunosuke stumbled backward, barely avoiding the second strike.
“Hahaha!”
Instead of fear…
The serial killer laughed.
“You wanna play too?”
His voice was filled with genuine excitement.
“You should’ve said so!”
He grabbed a rusted butcher’s knife from a nearby table.
Moonlight reflected from its edge.
Ren’s expression remained calm.
“Don’t panic.”
“He’s just a human.”
“Just another human.”
But the knife…
Made that difficult to believe.
Ryuunosuke lunged.
Wild.
Untrained.
Completely reckless.
Ren sidestepped at the last possible moment.
The blade scraped across his sleeve instead of his ribs.
Before Ryuunosuke could recover—
Ren drove the iron pipe directly into the man’s abdomen.
“GUH—!”
The air exploded from his lungs.
Another strike.
This time across the knee.
A sickening crack echoed through the room.
Ryuunosuke screamed.
His leg buckled beneath him.
The butcher’s knife clattered across the floor.
Ren kicked it away without hesitation.
“…”
For the first time…
The smile disappeared from Ryuunosuke’s face.
“W-Wait…”
“You…”
“You’re actually trying to kill me…”
“…”
Ren looked down at him.
His voice remained steady.
“No.”
“I’m stopping you.”
Ryuunosuke blinked.
“…What’s the difference?”
Ren answered quietly.
“The difference…”
“…is that the children you’ll never murder won’t have to ask that question.”
Silence filled the slaughterhouse.
Ryuunosuke stared blankly for a moment.
Then…
He laughed.
A dry.
Broken.
Mad laugh.
“Hahahaha…”
“You’re weird.”
“So weird…”
Ren raised the iron pipe once more.
His eyes held no hatred.
Only resolve.
The moon disappeared behind the clouds.
Darkness swallowed the room.
The sound of metal cutting through the air echoed one final time.
Volume 1: The Fourth Holy Grail War
Chapter 1: The Beginning Beyond Fate (Part IV)
The iron pipe fell.
THUD!
Silence.
The echo lingered throughout the abandoned slaughterhouse.
Ren remained motionless, his breathing ragged.
The blood-stained iron pipe slowly slipped from his trembling hand, striking the concrete floor with a metallic clang.
“…”
His heart pounded violently against his chest.
He had never killed anyone before.
Even knowing what kind of monster Ryuunosuke Uryuu was…
The weight of taking a life still settled heavily upon him.
“…”
Closing his eyes for a brief moment, Ren steadied his breathing.
“No…”
“If I had hesitated…”
“Hundreds of innocent people would’ve died.”
When he opened his eyes again…
His resolve had returned.
Without warning—
The familiar translucent interface quietly appeared before him.
Unlike before, several lines of text flowed across it in succession.
══════════════════════════════
Mission Completed.
Target Eliminated.
Verifying Timeline…
══════════════════════════════
Ren silently watched.
For several seconds…
Nothing happened.
Then—
══════════════════════════════
Original Event Confirmed.
Heroic Spirit:
Caster
Status:
Summoning Prevented.
══════════════════════════════
A second notification immediately followed.
══════════════════════════════
Calculating…
Calculating…
Calculating…
══════════════════════════════
“…”
The calculation continued far longer than Ren expected.
As though Astra Horizon wasn’t merely evaluating one person’s death…
But every consequence branching from that decision.
Moments later—
The interface finally stopped.
══════════════════════════════
Significant Plot Divergence
Confirmed.
Original Destiny Altered.
World Correction Accepted.
Reward Generated.
══════════════════════════════
Ren frowned.
“…World correction?”
The notification disappeared before he could dwell on it.
Instead—
Another screen quietly unfolded.
══════════════════════════════
Rewards Generated
□ Beginner Reward Package
□ Plot Divergence Reward
Claim Now?
YES / STORE
══════════════════════════════
“…”
Ren glanced around the blood-soaked slaughterhouse.
“…Store.”
Immediately—
══════════════════════════════
Rewards stored.
Inventory Updated.
══════════════════════════════
The interface vanished.
Ren nodded in satisfaction.
That was exactly the kind of feature he wanted.
No unnecessary interruptions.
No forced reward animations.
Everything could wait until he reached somewhere safe.
Before leaving…
Ren looked around one final time.
The worn leather grimoire still rested atop the bloodstained table.
The infamous…
Prelati’s Spellbook.
One of the most dangerous Mystic Codes in existence.
“…”
Ren stared at it for several moments.
Then…
He simply walked past it.
“…”
“There are things…”
“…better left untouched.”
Even Astra Horizon remained silent.
It neither encouraged nor discouraged him.
Ren quietly exited the slaughterhouse.
Several minutes later…
Orange flames rose behind him.
The old building gradually became consumed by fire.
By the time the authorities arrived…
Nothing would remain except ashes.
Neither the Spellbook…
Nor the countless horrors committed within.
Nearly an hour later…
Ren returned to his apartment.
The exhaustion finally hit him.
He collapsed onto the sofa.
“…Status.”
══════════════════════════════
Astra Horizon
Status Sheet
Name
Ren Aoki
Alias
Ren
Race
Human
Alignment
Neutral Good
Current World
Nasuverse
World Record
Nasuverse
└── Fate/Zero Timeline [Current]
Parameters
Strength
E
Endurance
E
Agility
D
Mana
E
Luck
EX
Personal Skills
Noble Phantasms
══════════════════════════════
Nothing had changed.
“…”
“As expected.”
The rewards hadn’t been applied automatically.
That was reassuring.
It meant Ren retained full control over when to claim them.
“…Inventory.”
══════════════════════════════
Inventory
Items
• Apartment Key
• Smartphone
• Wallet
• Identification Documents
• Bank Card
• ¥7,950,000
• ¥50,000 Cash
Rewards
• Beginner Reward Package
• Plot Divergence Reward
══════════════════════════════
“…”
Ren’s gaze lingered on the second half.
He mentally selected the first reward.
══════════════════════════════
Beginner Reward Package
Contents
• Identity Synchronization
Completed
• Financial Foundation
Completed
• Residence
Completed
• Language Synchronization
Completed
• Status Observation
Available
Claim?
YES
══════════════════════════════
“…”
Ren blinked.
“…Status Observation?”
He selected YES.
══════════════════════════════
Authority Integrated.
Personal Skill Acquired.
Status Observation
Rank: C
Description
Allows the Host to observe
basic information regarding
individuals recognized by
Astra Horizon.
Further functions will expand
as synchronization progresses.
══════════════════════════════
The notification faded.
Ren instinctively reopened his Status Sheet.
══════════════════════════════
Personal Skills
Status Observation (C)
══════════════════════════════
“…”
A faint smile appeared.
“Convenient.”
Not overpowered.
But useful.
Exactly what he hoped for.
Only one reward remained.
The true reward.
The one Astra Horizon had generated because Ren had successfully altered Fate.
He slowly selected it.
Immediately—
The atmosphere inside the apartment changed.
══════════════════════════════
Plot Divergence Reward
Evaluation
EX
Reason
Prevented the manifestation of
Heroic Spirit: Caster before the
Fourth Holy Grail War officially
commenced.
World Destiny significantly
altered.
Reward
True Summoning Permit
Compatible Individual Found.
Claim?
YES / NO
══════════════════════════════
Ren’s heartbeat quickened.
“…Compatible…”
His fingers tightened unconsciously.
He already knew.
Even before pressing YES.
Somehow…
He knew.
Taking a slow breath—
Ren accepted the reward.
The moment he did…
The room fell completely silent.
No lights flickered.
No violent explosion erupted.
Instead…
Countless particles of pale golden light quietly gathered at the center of the apartment.
Like stars descending from the night sky.
The air became warm.
Gentle.
Sacred.
A breeze that should not have existed stirred the curtains.
The light gradually took human form.
Long golden hair.
Elegant silver armor.
A white cloak gently fluttering despite the absence of wind.
A radiant spear rested lightly in her right hand.
Her emerald eyes slowly opened.
For a brief moment…
Neither of them spoke.
Then—
The woman looked directly at Ren.
Not with hostility.
Not with suspicion.
Only calm curiosity.
“…”
Her soft voice finally broke the silence.
“…Are you…”
“My Master?”
Ren stood frozen.
Before him…
Stood the King who had once ruled Britain.
Not as the Lion King.
Not as a Heroic Spirit confined to the Throne.
But as Artoria Pendragon (Lancer)—the woman who had reclaimed her humanity after the events of the Sixth Singularity.
And for the first time since arriving in this world…
Ren realized.
His journey beyond the horizon of fate…
Had truly begun.
End of Chapter 1