Chapter 36: Reverse Scale

Black flames seared the canopy that pressed down from above, waiting for the moment when the demon burdened with countless curses would be born into the present world.

The stagnant air was so sweet it was sickening. The walls pulsed like the entrails of some living creature. This place was, without question, another world.

"…Sorry. Just a little longer. I’ll have a fine meal ready for you soon, so hold on a bit more."

The boy spoke to the girl.
He didn’t expect her to answer.
He only had one role—to devote himself to her.

"Now then… let’s begin the final Holy Grail War."

---

All preparations were completed an hour before dawn. Using the moonlight as their guide, Shirou and the others made their way through the forest.

"This really the right way?"

At the rear, Lancer called out to Rin walking ahead.

"According to what Ilya said, it should be around here…"

Rin furrowed her brow, scanning the surroundings for the path leading underground to the Greater Grail.

Ilya had stayed behind at the Emiya residence. Since this would be the final battle, she herself insisted she’d only be a burden without any combat ability.

Shirou had been uneasy about leaving her alone, but Souichirou had agreed to protect her. With him there, she’d be safe even if something happened.

Right now, they had to focus on what was in front of them. Beyond this point lay a death ground. Even the smallest lapse could cost them their lives.

"…There it is."

Tracing a small stream, Rin discovered a massive slab of rock further upstream. A side opening seemed to be hidden there.

"There’s magecraft camouflage over it, but this is definitely the place."

The entrance was barely wide enough for one person to squeeze through. Just beyond it, a wall stood in the way.

An ordinary person would take one look and assume there was no path beyond, then turn back. But Rin reached out toward the wall.

"Yeah… it lets you pass through."

Without looking back, she slipped into the darkness. Bazett and Caster followed after.

"Shirou…"

Saber glanced back. What shone in her eyes wasn’t fear or doubt.

"――――It’s fine."

Shirou told her.

"I’ll be fine, Saber. I’ve already steeled myself."

What Saber feared was Shirou fighting against Shinji and Sakura.
While they prepared for this battle, Shirou had spoken of how he first met them.
For Shirou, Shinji had been an irreplaceable friend, and Sakura a precious part of his family.

"――――Saber."

Shirou’s eyes wavered for a moment before he quietly confessed:

"…I can’t be a Hero of Justice."

His words carried a faint sadness.

"Shirou…?"

"I used to believe I could save everyone. That was my ideal—that nothing and no one should ever be lost. But…"

He shook his head.

"I know now it’s impossible. I realized it when I learned Archer’s past… no, even before that—when I killed Rider. To save one person, you have to abandon another."

He let out a deep breath.

"If the day ever comes when I have to throw Saber away in order to save someone else… just thinking about it chills me to the bone."

To save ten, abandon one. If that’s what it means to be a Hero of Justice, then he could never be one.

"For me, Saber is the most important. No matter what, I don’t want to lose you. I don’t want to throw you aside. If I did, I’d become just like Archer. In the end, I could never be a Hero of Justice. So――――"

He cupped Saber’s face in his hands, whispering:

"I’ll be your ally. Yours alone."

"…Shirou. You…"

Before Saber could finish her words, Shirou kissed her.
Her eyes widened in shock.

"We’re going to survive. Both of us. No matter what."

"…Yes."

They held each other’s gaze. They wished the moment would last forever. Their feelings were as one.

But time never stops.

An awkward cough echoed through the space, making them both flinch.

"…Yeah, sorry to butt in, but if we waste too much time here, the sun’ll be up."

At Lancer’s remark, Saber panicked. Shirou, on the other hand, simply took a deep breath and nodded.

"Yeah, you’re right. …Let’s go."

He gripped Saber’s hand tightly and stepped into the darkness. Saber followed.

Lancer, shrugging with a weary "what a pain," brought up the rear.

They moved carefully along the damp stone slope. It was too steep to continue holding hands, so Shirou reluctantly let go.

The path stretched endlessly downward, as though leading straight to the abyss. After descending nearly a hundred meters, the space suddenly opened wide.

"Took you long enough."

Rin glared, her eyes narrow and sharp.

"S-sorry…"

Shirou apologized, then glanced around.

"It’s brighter than I expected."

All around, faintly glowing green moss lit the cavern.

"Alright, we don’t have the luxury to dawdle."

Caster spoke once Saber and Lancer caught up. Everyone nodded and pressed on into the dark cave.

"――――Still, this air is disgusting."

Lancer muttered with a groan. And he was right.

The air itself was wrong—thick with a sickening vitality, as though steeped in living flesh. The deeper they went, the stronger the feeling grew. Their destination had to be the source of this abominable energy.

Before long, they stepped into a vast chamber. A heavy, humid atmosphere pressed down on them.

"…Looks like this is where it ends."

Lancer strode forward. The cavern was as wide as a schoolyard, and at its center stood a silent giant.

The Berserker-class Servant, Heracles. His massive frame radiated dark mana as he loomed like an immovable wall.

"――――I’ve been waiting."

A voice rained down from above. Startled, they looked up—and there she was.

Twin gemstones shone brilliantly in the darkness. Legend said that anyone who met that gaze was turned to stone.

The Mystic Eyes of the monster Medusa――――“Cybele.”

"――――――――Hah."

And yet—there was no need to fear. They already knew well enough what kind of being she was.
A knight tutored by a magus of the Age of Gods and the queen of the Land of Shadows—when those two had combined their powers, no matter how fearsome her ability, it became meaningless.

Without the slightest sign of being weighed down, Lancer roared:

"Your opponent’s me, Rider!!"

He raised his crimson spear high, a bloodthirsty killing intent surging from him. Rider, in turn, gave a faint, amused smile.

"How unfortunate. You and I are a poor match. I’ll leave you to him."

At her words, Berserker let out a thunderous roar, dark magical energy bursting from him as he hefted his axe-sword.

"…So, no holding back, huh."

It was as expected.
Caster had already deduced that Shinji had gathered Servants at the church through the power of Command Seals.
And the reason Shinji had deliberately chosen not a drawn-out conflict, but a decisive, short final battle—was this.

Command Seals, used for temporary reinforcement. A forced unleashing of power while stripping away reason.
It was the same method Shirou himself had once used to forcibly draw out Saber’s strength.

Because this was to be a short battle, there was no reason to conserve anything. Tonight, the Matou faction had mobilized its maximum, strongest fighting force.

"…So, we’re going with Plan B."

Bazett muttered as she fitted her gloves tighter.

Since the Matou Grail could collect the souls of defeated Servants and resummon them, there was no room for reckless kills—or reckless deaths.
The battle had to be prolonged until their true objective—the destruction of the Matou Holy Grail—was achieved.

"You all understand, right? Stay wary of Assassin at all times. Other than that, stick to the plan."

Caster spoke firmly to Shirou and the others. She too would remain here.
Since Lancer had to occupy Berserker, the only one suited to face Rider—whose mobility was her greatest asset—was Caster, who excelled at long-range attacks.

That said, Caster was vulnerable if forced into close combat. For that reason, she would be paired with Bazett.
Though neither was thrilled about entrusting their back to the other, considering the opponents that likely awaited deeper within, this lineup was the only viable choice.

"…We’re handing you the real prize. Don’t screw it up."

Lancer grinned as he leveled his spear.

"Don’t you screw it up either."
"Yeah, yeah, I got it."

He brushed off Rin’s retort with a light tone, before charging Berserker head-on.
At the same moment, Caster fired off a magical projectile at Rider in greeting.

Taking advantage of the opening, Shirou and the rest dashed toward the exit on the far side of the cavern.

"…I won’t allow that."

Rider snapped her wrist, hurling her chained nail-sword toward them.

Bazett intercepted at blinding speed, deflecting it.

"Your opponent… is me."

Even as a human, Bazett possessed abilities on par with Servants. With Caster’s support, her combat prowess had already surpassed human limits.

"Come. You’ll be staying with me—until the moment they settle this."

---

Beyond the cavern, as expected, someone stood waiting.

"…Artoria."

Saber stepped forward in silence.

"Really… Shinji can be troublesome. To wake me again, when I’d already met a satisfying death at the end of battle…"

Yet in her eyes burned the clear light of reason.

"Still, it’s fine. I had wanted to cross blades with my reflection at least once."

With a faint smile, she locked her gaze on Saber.

"Don’t bore me."
"…I won’t."

Saber drew a deep breath and raised Excalibur.

"Shirou…"

Rin whispered.

"…Yeah."

Shirou bit down hard, staring at Saber’s small back.
If he could, he would stop her. If possible, he would take her place.
But he had his own role to play. Against Artoria, only Saber herself could stand.

"…Saber."

Shirou lifted his hand, the Command Seal glowing—the last one he had left.

"I’ll be fine, Shirou."

Saber’s voice was calm.

"We’ll survive together. And then—"

She smiled brightly.

"When it’s all over… let’s get married."

"…Yeah. We will."

Well, it wouldn’t be immediate—there’d be money to gather, preparations to make… but—

Shirou managed a faint smile, his resolve solidified.

"Saber. Draw out all your strength—fight Artoria!"

The Command Seal vanished, and a violent gale swept through the cavern.

With Caster’s magical reinforcement flowing into her, and with the powers of the King of Knights residing within—
Saber, the strongest Servant, manifested her true form.

The whirling storm of magical energy, the unbreakable armor, the overwhelming presence—her being dominated the narrow darkness of the cavern.

"Yes… that’s how it should be. Now, let us enjoy ourselves."

Artoria bared a feral smile and lunged forward.

Saber quietly swung her sword.

“――――Now then, let’s go.”

Pulled along by Rin, Shirou reluctantly began to run. Leaving Saber behind tore at his chest. As he ran, he pressed the hand opposite the one that bore the Command Seal tightly against it, desperately praying.

Please… be safe――――

---

They pressed deeper into the pitch-dark cave, racing through a passage filled with the raw pulse of life itself. The oppressive air bore down on them. Not figuratively—literally heavy. A torrent of dense magical energy, thick enough to see, was pouring in from deeper within the cavern.

The final gatekeeper waited ahead. Two Servants remained, but Assassin was not the type of Heroic Spirit to fight head-on. He would be hiding, waiting.

Which meant only one enemy awaited them. Facing that gatekeeper was his role alone.

Preparations were complete. All that was left was――――

“――――Archer.”

Rin’s voice carried a sorrowful weight as she whispered.

He stood with his back to the passage’s exit. The man who had cast away his life to carve open the future of the one he loved. A man who had fulfilled his wish, only to be roused again by Shinji, forced into service as a weapon of war.

He deserved to be put to rest. With that thought, Shirou clenched his fist tight.

“…Been waiting, Emiya.”

“Shinji…!”

Shirou’s breath caught as Shinji stepped out from behind Archer. He hadn’t expected him here. He thought Shinji would be waiting alongside Sakura at the Greater Grail.

“Just as I thought. If anyone made it this far, it’d be you two.”

“…You’ve got some nerve, showing up here like it’s nothing.”

Rin reached for the trump card hidden at her back. Shirou stopped her.

“…Shinji. I’ll say this one last time.”

Rin shot him a reproachful look, but Shirou ignored it.

“Stop this.”

Meeting Shirou’s earnest gaze head-on, Shinji slowly shook his head.

“Can’t do that. If I stop here, that’d be betraying Sakura. I swore I’d stay by her side—her ally, until the very last moment.”

“…I see.”

Shirou let out a long breath. Sakura’s ally. That was what Shinji said. Just as Shirou had sworn to stand by Saber, Shinji had resolved to give everything for one person alone.

Then there was nothing more to say.

“…Tōsaka.”

Shinji’s eyes turned to Rin. She bit her lip, glaring at him with an expression caught somewhere between anger, sorrow, and something harder to place.

“Sakura’s further in. If you want to go, then go.”

“…What are you playing at?”

Rin frowned at him, suspicious.

“Nothing. Just thought… maybe that wouldn’t be the worst thing.”

“…?”

Shirou and Rin looked puzzled. Shinji gave a faint smile.

“I… never managed to be a proper big brother to her.”

Rin’s expression faltered. Whether what surfaced there was anger, grief, or envy, she couldn’t say herself. But Shinji went on regardless.

“Her true family… was always you. So if you’re the one to stop her, maybe that’d be happiness for her.”

He gave a small shrug.

“Not that I know if you can stop her. She’s strong now. To be blunt, half-baked strength won’t even scratch her. But… if you’re still going, I won’t get in the way.”

“…I’ll go.”

Rin’s expression hardened as she stepped forward. True to his word, Shinji made no move to stop her.

As she passed, she paused only once at his side and murmured, barely above a whisper:

“…Thank you. For being by Sakura’s side… that much, I’m grateful for.”

Shinji only shrugged.

“…Just self-satisfaction. In the end, I couldn’t save her.”

Rin gave no answer to his bitter self-mockery and walked deeper into the cave.

After watching her back fade into the darkness, Shinji turned his gaze back to Shirou.

“…Then, let’s get started.”

Smiling faintly, Shinji pulled a spider from his pocket.

“――――Do it, Sakura.”

At his words, Archer moved. But his action defied Shirou’s expectations.

Instead of striking at Shirou, Archer’s arm pierced Shinji’s heart.

“…Eh?”

Shirou froze in shock. Blood spilling from his lips, Shinji still smiled as he spoke.

“…I made Sakura use a Command Seal.”

“A Command Seal…?”

“Of the two left… the first ordered Archer to fight until he killed you. And the second――――”

Shinji’s smile deepened.

“…was this: ‘Etch the existence of Matō Shinji into your very soul.’”

“…What are you saying…?”

Shirou stared, dumbfounded, as Shinji’s soul slowly sank into Archer’s body.

Ordinarily, such a thing was nothing but suicide. To inscribe one’s soul onto a Heroic Spirit was like dropping a single drop of ink into the ocean. It would thin, fade, and vanish in an instant.

“But overturning such laws… that is the true purpose of a magus.”

It was much the same phenomenon that had happened with Saber.

The current Archer, corrupted by “All the World’s Evil,” had been stripped of both reason and will. He was little more than an empty vessel, a shell of data as a Heroic Spirit.

By pouring his soul into that shell, Shinji recreated the same state as Saber had been in at the start. It was a forbidden trick he had conceived only because he had been studying Saber’s condition so obsessively.

“…Shinji? Is that really you?”

Shirou asked. Slowly, Archer opened his mouth.

“…Now then. Let’s begin the final Holy Grail War.”

---

“――――So this is it.”

A dark place. Cold air. The quiet sound of water. At last, their vision opened up. Beyond the darkness lay an immense space.

An endless dome and the same black void they had once seen. That was the beginning of the battle—and its final destination. The system that had continued to operate for two hundred long years rested there.

It looked much like Ayers Rock, but its summit had collapsed inward, and upon it a massive magic circle was inscribed. Illya had once told them: that was the true form of the Greater Grail.

The heart of the ritual. The circular crown corridor. The world’s core. The Cup of Heaven. Overflowing with immeasurable magical power, it created an alien realm worthy of its name.

And from its center, a black pillar stretched up toward the heavens. The only light in the vast cavern was the magical pulse radiating from that pillar.

“That’s… ‘All the World’s Evil’…”

The magical energy flooding the Greater Grail was inexhaustible. Even if every magus in the world greedily drew from it, it would never run dry. With so much power, indeed, any wish could be granted.

Shirou looked up. And there—she was waiting.

She had changed greatly since they last saw her. Her hair had turned pure white, her flesh wasted away until she resembled an old crone.

Yet she caressed her own abdomen with an enraptured expression.

“――――It’s been a while, Sister.”

Sakura smiled faintly.

She should have been broken beyond saving, yet she smiled, her eyes clear with will, her lips forming words.

“…Sakura.”

“Look. It’s almost born. My precious little baby… just a little longer――――”

A chill ran down their skin. What swelled within Sakura’s belly radiated the same magical energy as the black flames burning behind her.

“…To call something like Angra Mainyu a ‘precious little baby’… You’re playing quite the mother, Sakura.”

“Ehehe… That’s right. I’m going to be a mother.”

Rin had meant it as scorn, but Sakura only smiled with genuine happiness. And that made it all the more terrifying.

“My baby… so sweet, so dear… the child of me and my brother.”

“…Brother?”

“Yes. Long ago… only once, we shared our bodies. Back then, I kept the seed my brother gave me. I didn’t absorb it—I preserved it. So that one day… when the time was right… I could conceive.”

Blushing, Sakura beamed with joy.

“My brother only sees me as his little sister. But I love him. I’ll give birth to his child, our child, as proof of that love…”

She hummed happily to herself, but Rin cut her coldly:

“What proof of love? All this time you’ve been deceiving the brother you claim to love.”

“I haven’t deceived him.”

Sakura’s smile shifted. The innocent girlishness vanished, replaced by something alluring, wicked.

“He’s only misunderstanding things on his own. But why correct him? As long as he thinks I’m broken, he’ll be kind to me. He’ll stand by me. If he ever knew I wasn’t broken, he’d surely leave me. I can’t have that. I won’t allow it!”

Her cheeks puffed in a sulky pout. Rin retorted:

“If he found out you weren’t broken, he’d rejoice.”

“…That’s a lie.”

Sakura declared flatly.

“My brother is kind to me because I’m broken. Otherwise… who would ever want to stay with a monster like me?”

Her expression drained away, leaving her face blank. In that emptiness, she whispered:

“I eat human flesh. For ten years since I was taken in, I even learned to tell the difference between the taste of semen and of meat. Who would ever willingly be with something so defiled? He stays with me out of pity, because I’m broken. That’s the truth. I know my place.”

Sakura puffed out her chest proudly as she said it. Rin was struck silent.

Not broken—yet broken beyond repair. Her will and emotions still clung together, but everything else… utterly shattered.

“…Sakura.”

Rin fought to hold back the tears threatening to spill.

“Stop this.”

“I can’t. I do like you, Sister… but I will absolutely give birth to my brother’s child! It’s our love, our bond. I won’t yield this to anyone!”

Sakura raised her fist high.

“…Then I can’t allow it to be born.”

If it were just a normal baby, I would have let her have it. That “rather…” part still bothers me, but—my little sister said she loved him. I wanted to grant her wish.

But to bring forth the Angra Mainyu into this world… that alone…

“...We have Caster on our side. She can purify your body, make sure you can give birth to a proper child! That’s why, I’m begging you! Please, give up on this child, just this one!”

Rin pleaded as if coughing up blood. This was the final chance.

If Sakura wasn’t completely broken, then there was still hope. If she asked Caster, she could be saved. Rin would gladly pay any price to make it happen.

If they demanded her life, she would offer it. If they told her to endure the ten years of suffering Sakura had lived, she would gladly bear it.

“Please, Sakura…”

Pressing her forehead to the ground, she continued to beg.

“...B-but… my brother’s sperm only exists for this child...”
“No matter what it takes, I’ll squeeze every last drop out of that bastard and give it to you!!”

Seeing Sakura falter ever so slightly, Rin shouted as if to hammer the words in.

It was a cry from the depths of her heart. If it meant saving Sakura, she’d wring Shinji dry until he was nothing but a husk.

“...Really?”
“I promise!! So—!”

Rin’s face lit up with joy at the sight of Sakura wavering.

That was when it happened.

A raspy old voice echoed through the great cavern.

“—That cannot be allowed.”

Rin’s breath caught. Sakura suddenly writhed in agony.

“To think you’d change your mind at the last moment… did you truly believe I would permit it?”
“Z-Zouken!?”

A shiver of pure dread shot through her, and Rin broke into a run.

“Sakura!!”

Rin screamed. But—

“Ah, it’s already done. No matter how you call out, it’s useless now, Tohsaka’s daughter.”

The voice came from Sakura’s mouth.

“Sak…ura…?”
“As her guardian, I had thought to let her take the honor of seizing the Grail…”

Cackling through Sakura’s lips, the girl before Rin came to a halt.

“But to fill her with fleeting hope at the very last moment, only to cast her down into the abyss of despair—what a cruel elder sister you are. Hmph. All thanks to you, I had to do something as vile as devouring my own granddaughter.”

With Sakura’s throat trembling under his control, the old magus muttered.

“...Zouken.”

Her body shook. She had been a single step away from saving her beloved sister.

Her emotions froze. Every thought converged into one.

Just one final push. One more step and she would cross that last line.

In a voice drained of all warmth, Rin addressed Zouken.

“...You. What did you do to my sister?”

“Hmph. Seems I’ve overestimated you. Your wits are rather duller than I thought.”

With Sakura’s face twisted into a lewd grin, Zouken sneered.

“I simply swapped her head out and took her over, that’s all.”

Those words became the final push.

“—Ahahahahahahahahahahahahaha!!”

Rin laughed—harsh, wild, unrestrained.

Clutching her stomach, tears welling in her eyes, she laughed.

At the sight of her hysteria, Zouken’s face showed a flicker of unease.

“...Broken, have you?”

To that question, Rin’s laughter shifted into a smile, her voice dripping with venom.

“You’ve pushed me this far… you don’t actually think—”

Zouken’s grin vanished. The vast cavern was flooded with a killing intent so chilling it made the air itself tremble.

And for the first time, the centuries-old magus felt fear before a girl who hadn’t even reached her twenties.

“—That you’ll get away with this, do you?”