Interlude: "……Understood. Go to hell, Master."

The first time he learned about women was when he had just entered middle school. It was pure coincidence that it caught his eye amidst his desperate pursuit of magecraft—the mysteries of the occult.

A pitiful girl abandoned by her parents—that was how he had labeled her. So, he treated her with a certain degree of kindness. That’s why, when he saw her swaying unsteadily, he called out to her as usual. It was nothing more than concern for her well-being. But when she turned around and he saw the state of her mouth, he was left speechless.

Crimson blood stained the lips of the girl who should have been young and innocent. Bright red, like a child with no table manners smearing ketchup around their mouth.

"Wh-what the hell happened…?"

At first, he thought it might be some strange illness. Or perhaps she had hurt herself by bumping into something.

But it was neither. The place the girl had emerged from was a door he had never noticed before. Overcome by indescribable terror, he cautiously peered inside—and there, he witnessed hell.

Countless corpses filled the space. Every single one of them was mutilated beyond recognition.

"Ah… AAAAAAAAAAAAHHH——!!"

He ran. He averted his eyes from everything, dashed into his room, and buried himself under the covers.

What he had just seen had to be a lie. When he woke up, he’d scold his stepsister for her usual gloomy expression and throw himself back into his magecraft training.

So, for now, he would sleep. He’d sleep without thinking about anything.

It’d be fine. When he woke up, surely——

"……Huh?"

When he came to, he was in a dark room.

And standing before him was his stepsister. Her appearance was so——alluring that his cock stiffened instantly.

He knew about these things. He’d even played around with a girl before, treating her as a "sample." So, he immediately realized he was aroused—and was horrified.

Because this was his stepsister. Even if they weren’t related by blood, he had never seen her that way. Yet now, he couldn’t stop himself from wanting to pin her down.

"……The hell’s wrong with me?"

He desperately clung to reason. If he gave in to instinct, there’d be no going back.

The fear of losing himself held him in place.

But he was the only one who stayed still.

The room was filled with other men—all of them naked.

"Sh-she’s mine… That girl… is mine…"

It was the height of depravity. With their erect cocks swinging, the men closed in on his stepsister. Some were already dripping with cloudy precum.

"Th-this is bullshit!!"

He lunged forward. It was the recklessness of youth—an escape born of inexperience with women.

Though he was just as naked and hard as the rest, at least he had tried to protect her——only to end up approaching her instead.

That was his undoing. He should have just crouched down and endured until it was over. But because he got too close, he was ensnared.

Her body was far from mature, yet there was an eerie elegance to it—an unnatural allure. Her scent, her gestures, her face, her body—everything about her seemed designed to seduce men——and just like that, he lost himself too.

The men fought to claim the girl. They forgot time, spared no moment for sleep, and poured out their desires endlessly.

A pack of brutes using the girl—now radiating a dizzying sensuality—as their plaything. But in truth, they were the ones being devoured.

Before they could break her, the men’s flesh was torn apart as the girl began to chew. Even as they realized their bodies were being eaten, their faces twisted in ecstasy.

A space ruled by madness. And yet, he survived. He was the one who lived.

"Sakura… You’re…——"
"……Disgusting."

Watching Sakura grimace as she chewed on the flesh, Shinji let out a sigh.

Whether it was because he had been touched by madness or not—even he didn’t know.

"Of course some old bastard’s meat wouldn’t taste good. God, you’re so slow——"

What the hell was he even saying?

With a self-deprecating smirk, Shinji held out his arm to Sakura.

"Try this instead. Bet it’ll taste way better."

He just pitied her—his stepsister, forced to eat the revolting flesh of middle-aged men while complaining about the taste.

If nothing else, he wanted her to have something delicious.

Sakura tossed aside the corpse and approached. She opened her small mouth and took Shinji’s finger between her lips.

There was no pain—just a ticklish sensation.

"Heh, just sampling it?"

Shinji chuckled wryly as Sakura tilted her head slightly before nodding.

Her gesture made him laugh. For the first time in his life, he laughed wholeheartedly.

"Good?"

He asked as his stepsister licked his finger with single-minded focus.

When Sakura nodded again, he laughed once more.

"Just gonna lick it? Not gonna bite?"
"……Too precious."

At her quiet murmur, Shinji laughed until tears streamed down his face.

"If all you wanna do is lick, you can do it anytime. Eating nothing but crap’s gotta suck, right? At least let me give you something to cleanse your palate. What kinda big brother would I be otherwise?"
"……Mhm. Thank you, Onii-chan."

Sakura returned to the corpses, sinking her teeth into them and resuming her meal. Shinji silently watched.

From that day on, Shinji survived by observing Sakura’s meals—always offering his finger for her to lick at the end.

Strangely, his cock only reacted that first day. After that, he never felt arousal in front of his stepsister again.

The reason was obvious. She had made him an exception. The other men, intoxicated by the poisonous woman’s miasma, were devoured without a shred of sympathy from him.

He just couldn’t stand the way her face twisted in disgust as she ate.

"Seriously, these guys are all defective. Probably lived off junk food and bad habits. No wonder their meat tastes like shit. Poor Sakura, having to put up with this."

His dark humor didn’t reach the girl. After all, she had been broken long ago.

The only reason she kept him alive was because he tasted good. If his flesh ever lost its flavor, she’d kill him without hesitation.

But he never stopped coming.

And so, the present. He knew that the head of this household, Zouken Matou, held the Servant summoned by Shirou Emiya in special regard.

He had heard it directly from the girl herself—the anachronistically dressed figure who occasionally appeared during his stepsister’s meals. Apparently, she had been sealed away here for so long that she craved someone to talk to.

Her name was Artoria. During the final stages of the previous Holy Grail War, she had fought against Archer’s Servant before being swallowed by the Grail—losing most of her sense of self but gaining a second life in return.

All she retained was her name and an unshakable thirst for the Holy Grail. She had no attachment to her past, not even clear memories of it. That was why she formed an alliance with Zouken, whose only goal was obtaining the Grail.

She didn’t care about anything else. No matter how gruesome the murders or acts of cannibalism before her, she never batted an eye. As long as she obtained the Grail in the end, nothing else mattered.

"——I hate you."

When Shinji spoke, Artoria smiled and said, "I see."

It was unusual for her—having lost most of her sense of self and with her emotions dulled.

"I don’t dislike you, Shinji. It never gets old watching you keep playing the role of your little sister’s dessert, even when you could be eaten at any moment."

He wasn’t sure if she’d always been like this, but this woman was a born sadist.

Letting out a dry laugh, Shinji thought of his best friend.

Ah, if I let her meet that guy, things’ll go south real fast…

And so, dragging along the scapegoat he’d summoned as Artoria’s cover, he confronted Shirou.

If he’d activated his Noble Phantasm, Blood Fort Andromeda, he could’ve fought under favorable conditions… Looking back now, it was a reckless move. But he’d been impatient—he had no way of knowing when Zouken would make his real move.

His plan was to take out that guy’s Servant and force him to retire early.

But he lost. He’d assumed that hotheaded idiot would self-destruct if provoked, charging in with a suicide attack. After all, they’d known each other since middle school—he thought he understood him well enough.

Taking the Master hostage would render any Servant powerless. No, even without that, that Saber was already a puppet.

What he hadn’t expected was Shirou’s strength. Creating a Noble Phantasm was absurd. In the end, the instant Rider shifted her focus to kill Saber, Shirou struck.

"——Emiya got what he deserved. I tried to help him. But he just…"

Watching over his little sister’s meal as usual, Shinji muttered.

Even if it was under Zouken’s orders, staying in that house had allowed Sakura to remain human. So, in a way, this was his way of repaying her.

That idiot should’ve just abandoned his Servant and gone back to his normal life.

That way, no one would’ve gotten hurt.

"...Big Brother."

Sakura whispered sweetly—her usual plea. When he offered his hand, she happily began licking it.

A familiar habit.

"...You never get tired of this, huh?"
"Ehehe…"

Everyone’s an idiot. Zouken’s no exception. Anyone involved with magecraft is a damn fool, good-for-nothing scum.

"Hey, Artoria."

"What is it?"

"All you care about is getting the Holy Grail, right?"

"Yes, that’s correct, Shinji."

"Then——"

Artoria smiled cheerfully at Shinji’s proposal.

"Ah, you——that’s why I like you. But now isn’t the time. And that was far too careless."

With those words, Artoria mercilessly drove her hand through Shinji’s abdomen.

"...What the—?"

"My Magic Resistance has severed the connection between this thing and Zouken’s main body. But if I let it go, it’ll report back to him immediately."

Crushing the worm she’d extracted from Shinji’s stomach, Artoria spoke.

"Have Sakura heal you. A wound like this should close easily. And don’t say anything reckless again. Wait until the time is ripe…"

"...Yeah, I will. When that time comes…"

"Indeed. I shall become your sword. I’d far prefer a jester like you over that wretched monster. But if you’re going to dance, do it well. The jester I knew… danced magnificently to the very end."

Her murmur carried a hint of nostalgia.

"...Huh. So, you’re remembering a bit of the past?"

"No, hardly anything. But I do remember that man quite well. He was amusing—always making us laugh."

"His name?"

"...A troublesome question. I remember how he made me laugh, but I can’t recall it."

Shinji laughed as she furrowed her brows in frustration.

"Well, there’s only one jester in your legends, so…"

"Oh? You know it?"

"Pretty sure it was… Dinadan?"

"Dinadan… Yes, that was his name. He was… truly entertaining. I sense something of him in you. Though he was far more skilled—never leaving behind such a pitiful result as you might."

"...Sounds like he was a real favorite."

"Indeed. Speaking of him brings me joy."

The former king looked thoroughly pleased. Given her legends, perhaps that was only natural.

Dinadan the Jester. He had played the role of bridging the gap between king and knight, preventing discord at the Round Table, turning everything into laughter.

It was precisely because he was killed by Mordred that the Round Table shattered and Britain fell.

For King Arthur, his importance was no less than that of her other closest retainers.

"...Hah. Still, you’re awfully talkative today."

"Yes. It’s been long since I’ve been outside. And your schemes are truly entertaining. You have the skill to abandon everything now and live a decent life, yet you choose only ruin and despair. I find that delightful."

"...Shut up. I just… want to let Sakura eat something good."

Turning his face away but still letting his little sister lick his fingers, Shinji heard Artoria speak again.

"Could you become a Dinadan…?"
"What’s the point if I die halfway…?"

He didn’t want to be compared to a jester who died before his story was finished. As Shinji grumbled, Artoria laughed.

"Ah, true. Then dance properly to the end, Shinji."

"...That’s the plan."

While admiring the moon, the witch sang softly.

“Saber’s condition is excellent. The plan is flawless. At last, we can make our move.”

Resting her head on the witch’s lap was a black-haired girl, fast asleep.

“You look confused, Archer.”

Standing in the garden with a puzzled expression, the bow-wielding warrior met the witch’s smile.

“…That girl is Saber?”

“Yes, exactly. Don’t tell me you didn’t know that much?”

“What do you mean…”

As Archer frowned, Caster explained.

“When Shirou Emiya performed the summoning, the sheath of the Holy Sword embedded within him served as the medium, which made King Arthur the highest priority candidate among all Heroic Spirits. There are other spirits connected to Avalon, but none of them—Merlin, Morgan, or even Accolon—would be summoned ahead of King Arthur, who offered the Holy Grail as a bargaining chip with the world. Unless she herself relinquishes that wish, of course…”

She murmured while stroking the sleeping girl’s hair.

“But Shirou summoning King Arthur introduces a serious contradiction into the world. After all, Artoria Pendragon has already been summoned. Other Heroic Spirits might be duplicated—like Heracles, who could be summoned as Saber, Archer, or Berserker depending on compatibility. That’s possible because they’re just extensions of the Heroic Spirit named Heracles. Even if multiple instances exist simultaneously, no contradiction arises. But Artoria is different. Her true self is still alive. So any projection of her must carry her actual will. There can only be one. So what do you think happens if you try to summon another version while one is already active?”

“…The one summoned first gets her spirit, and the one summoned afterward only receives her soul. And so, to supplement the missing spirit, the world would—”

“No, Archer. That’s not it. Not exactly. You’re misunderstanding the key part.”

“What do you mean…?”

Seeing Archer’s confusion, Caster continued.

“King Arthur is a hero who’s destined to become a Heroic Spirit. Because of that, her legend is already etched into the Akashic Records. A space has already been prepared for her to eventually ascend to the Throne of Heroes. Shirou Emiya didn’t summon her per se—he drew forth the data the world had prepared in anticipation of her future apotheosis.”

“…Sorry, but I’m not following.”

Her abstract explanation earned a deep furrow from Archer’s brow.

“Put simply, he didn’t summon a true Heroic Spirit. He summoned the blueprint of one—the world’s record of what King Arthur should be. Hair this color. Eyes that color. Swordsmanship of this caliber. This past. These Noble Phantasms. All of that… but without a core. So that ‘data’ was forcibly grafted onto a compatible soul and cobbled together into a makeshift King Arthur to respond to the summons.”

“W-What the hell… Then, Hino Satou is—!!”

“Yes. Just an ordinary person who got dragged into this. One among countless drifting souls in the Root—no connection to Shirou Emiya or King Arthur whatsoever. He’s just… a mannequin, a dress-up doll used to make that illusion of Arthur work. But at the end of the day, that soul is still Hino Sato’s. Which means he’ll never become the real King Arthur. He’ll never master the sword, never understand how to wield a Noble Phantasm. And, apparently, when he looked in the mirror, he noticed it himself—his appearance is already starting to revert back to what it once was.”

“W-What…?”

“His eyebrows, the shape of his ears—little things. He said they felt oddly familiar. Of course they did. They were features from his face when he was alive.”

Caster’s words left Archer wide-eyed.

“Then… Hino could return to his original form just by doing nothing?”

“If only it were that simple. The Arthurian data had a huge influence on how his body was shaped in the first place. His gender is different now, his hair and eye color, too. So even if some of it reverts, it won’t be complete. Eventually, he’ll become… broken.”

“B-Broken…? Why…”

“Think about it. Right now, he’s surviving only because he’s become something completely different. The sex change, the other abnormalities—he can suppress them because they’re all overshadowed by the larger confusion of becoming someone else. But if that confusion fades, the smaller contradictions will start to come to light. He’ll become hyper-aware of the fact that his gender is wrong. And when that happens… it’ll destroy the mental defenses he’s been clinging to.”

“His… mental defenses?”

“He’s practically in a state of constant escapism. ‘This is another world. I’m someone else now.’ And on top of that, ‘I have someone I must protect.’ He’s been reinforcing that kind of self-hypnosis nonstop just to keep himself together. But if the moment comes when he’s forced to acknowledge ‘I’m still me,’ the rest of reality will come crashing down. When that happens, he’ll unravel in an instant.”

“N-No way…”

Seeing the look of dread on Archer’s face, Caster smiled gently.

“Don’t worry. I’ve made preparations. I have a dream—one of walking into the future together with Soichiro-sama… And for that, I need Saber’s power. I wouldn’t do anything to break her.”

Caster spoke while gently stroking the girl’s cheek with a look of tenderness. Archer looked visibly shaken.

“You…”

“Once I’ve claimed the Grail, I’ll release you all too. So long as you don’t interfere, I’ll even grant a few of your wishes. For instance, I could materialize Saber into a true human body—something I’m quite capable of.”

“…Why?”

“To be honest… I just can’t stand it.”

Caster muttered the words, as if to herself.

“I too… was toyed with by the gods, my fate twisted again and again. I was force-fed false love, coerced into betrayal over and over… Maybe that’s why I feel sympathy for Hino, used like a tool to correct the contradictions of this world. And I can’t deny I’ve enjoyed watching that boy desperately fight to protect someone precious to him.”

Caster looked up at the moon.

“I stripped away Arthur’s data, leaving only the minimum required traces of Hino Sato’s soul, then recalibrated everything. That’s why his hair is black now, and his eyes a dark brown. If he sees himself now, I imagine he’ll finally recognize himself. And yet, when he wakes up… perhaps instead of breaking, he’ll even feel grateful for reality.”

“What are you…”

“It’s simple. I’m letting him dream.”

“A dream…?”

Caster gave a sweet smile, like a child who’d just pulled off a prank.

“Right now, in his dream, he and Shirou Emiya are newlyweds, having a blissful little life together.”

“…What?”

Archer’s face twisted in disbelief as Caster described the dream she was showing Saber. When he heard how embarrassingly girlish it was, his mind practically went blank.

“…You…”

“Just so you know, this is by far the easiest and most reliable method. If you want him to come to terms with reality—”

“Wait… Wait, hold on. That’s just—”

“If he’s going to fall in love with a boy, it’s far more convenient to do it in a girl’s body, don’t you think?”

Archer turned his eyes away from the dazzling smile on Caster’s face and looked at Saber with something close to pity.

“Didn’t you say you hated the gods for planting false love in you?”

“Oh, I do. That’s exactly why I’m just showing Hino a sugary-sweet dream. A dream where a boy he has some emotional attachment to treats him completely as a girl and showers him in affection. That’s all. I’m not brainwashing him or anything.”

“No, that’s… pretty much brainwashing.”

“…Shall I show you the same dream?”

“Caster. More importantly, let’s finalize tomorrow’s assault plan on the Matou estate.”

Suddenly changing the subject, Archer’s expression hardened. Caster gave him a tired look.

“…Fine. Barring complications, we’ll launch the attack tomorrow morning. I assume you understand—the biggest threat is the Shadow. Once it catches you, that’s it.”

“Do we have a countermeasure?”

“In the worst case, I’ll have Saber use the Holy Sword. If that happens, I’ll need you to hold off both the Shadow and Artoria temporarily.”

“I have no objections. If it will bring that thing to an end, I’ll gladly play my part.”

“Good. Then die for my victory, Archer.”

“…Understood, my temporary master. My life is yours to command—but if you’re going to use it, make it count.”

“Of course.”

Beneath the moonlight, the bowman and the witch struck a pact.

“…Shirou, don’t touch me there… nnh… geez… ehehe…”

Saber murmured in her sleep, squirming slightly. The two exchanged a glance.

“Seems like the moment’s close… Her consciousness is beginning to return.”

“…Was this really the right thing to do?”

Archer placed a hand to his head, but Caster just laughed.

“I’ll tell you a fun little story.”

“A fun story?”

“Archer… You know how people always talk about equality, right? But the truth is, it doesn’t exist. Some people are born with everything, and some have nothing. There are those blessed with talent, and those who are hopelessly dull. Humans—each and every one—are built differently. And when it comes to gender differences…”

“What are you getting at…?”

Caster spoke with an enigmatic expression.

“Men and women are different down to the structure of their brains. Men prioritize logic, while women tend to prioritize emotion. That’s not just a stereotype—it’s neurological. Of course, there are logical women and emotional men, but those are just individual variations. Even in communication—did you know men use only part of their brain to speak, while women use their entire brain? It’s not universal, but… trying to move a woman’s body using a man’s sense of self—it doesn’t work. The biological blueprint is just too different.”

“So that’s why you’re trying to make Saber more like a woman…”

“Exactly. I told you, didn’t I? I have no intention of breaking her. If she stays locked in her male perspective, she’ll inevitably collapse.”

“Caster…”

“And besides… I really want to see Saber flustered at how girly she’s becoming…”

“—Hey! Don’t tell me that’s your real reason!?”

“Anyway! I’m counting on you tomorrow, Archer!”

Ignoring his outrage, the infamous witch cheerfully skipped off toward the bedroom of her master, a man named Soichiro Kuzuki.

Archer muttered with scorn beneath his breath.

“…Understood. Burn in hell, Master.”