Shirou, who returned from the Fairy Kingdom

However, what Shirou Amamiya did was the complete opposite of an explosion.

Shirou carefully selected the amount and location of the explosives he set up in order to delay the enemy's advance, rather than intending to blow the entire mansion to smithereens.

Using bombs underground without affecting buildings above ground—this is clearly a more sophisticated explosive technique than mere demolition.

Of course, it was also one of the skills he honed in Britain.

"Ugh! Damn it...!"

A few seconds later, Zouken Matou crawled out of the rubble, covered in dust and dirt.

He couldn't understand how Shirou managed to infiltrate and evade the saber-winged beetles' spies while planting explosives tonight.

Of course, he couldn't imagine it.

Because the explosives weren't planted tonight.

Even earlier—

My first day staying at the Matou residence.

When Shirou sneaked out at night to visit this magic workshop, he "casually" left a small gift for the Insect Master.

The Magic Workshop is the domain of magicians.

A magician in his own workshop is invincible, so Shirou deduced that if he were to fight Zouken Matou, he must stay as far away from that workshop as possible.

The explosives were originally prepared just in case, but they actually came in handy.

the other side.

Having been manipulated unilaterally time and again, Zouken Matou's rage reached its peak.

His hunched body trembled violently from the swarming insects inside him as he glared angrily at the two men ahead of him—

"?"

Shirou Amamiya was gone; only the girl stood quietly at the end of the passage.

By the time he realized what was happening, it was too late.

"Shh!"

Shirou emerged from the darkness behind the old magician and swung his blade toward his neck.

Zouken Matou's head flew off and rolled to the side with a "gurgle gurgle".

Having landed a successful blow, Shirou pressed his advantage, slashing down diagonally from his left shoulder with a second strike.

"Stab!"

The blade pierced through the human body unimpeded, and the monster that had ruled the Matou family for centuries was simply cut in two without any resistance...?

In an instant, the old man's short body transformed into an endless swarm of blade-winged insects, which swept towards the red-haired boy like a black storm!

"Brother Shirou!"

Upon seeing this, Matou Sakura screamed in surprise.

As expected, ordinary physical attacks have very limited effect on Zouken Matou.

Shirou remained calm and composed, as if he had anticipated all of this.

He let the insects gnaw at his skin, and with his right hand, which had released the chain blade, he plunged directly into the depths of the swarm.

It seemed to be groping for something, and then it grasped one of the insects.

"Ah, I found it."

"Fizz!"

Instantly, the swarm of insects that were tearing at the boy stopped moving as if a pause button had been pressed.

Although Zouken Matou was small, he had stored a large number of insects, more than a thousand, which covered the surrounding area densely.

However, Shirou instantly found the leader of the nearly one thousand insects—the only brain insect possessed by Zouken Matou's consciousness.

This is an incredible skill.

On one hand, his "Eye of the End" continues to work, and on the other hand, it also stems from the keen insight accumulated from countless battles, the "Mind's Eye (True)".

Within Zouken Matou's "life system," the brain worm only serves as the central nervous system, without any corresponding countermeasures, since he never imagined that he would be captured alive.

So Shirou injected only a little magic into the brain worm and used a simple spell to seize control of the swarm.

"Okay, try giving the order—"

The red-haired boy said calmly as he plucked the wings from Matou Zouken (the brain worm).

"All insects except the old man... commit suicide."

Crackling...

Black insects rained down from the underground passage, and the broken insect remains instantly covered the ground.

The first battle after their return was thus decided.

------

Volume 1, Chapter 11: Nature

"Is this the real body?"

Shirou examined the brain worm struggling and writhing in his hand.

The little thing is quite cute.

"Gulp... Kill me!"

Despite lacking vocal organs, the brain worm emitted a sharp, comical sound reminiscent of a defeated female knight.

"I reject."

Shirou immediately saw through Zouken Matou's lies and the mystery of his immortality.

"Just as I expected, it will transfer to the next insect (container) the moment it is killed... Did they set up such a spell? Hmph, I won't fall for it."

The amber pupils reflected the old magician's ugly and weak appearance.

Even Zouken Matou, would he waver when he saw his own disgusting true form?

Shirou sensed the emotional fluctuations in the insect in his hand, but he was indifferent and spoke words in an extremely calm tone that gradually filled him with despair.

"You really went to great lengths to save your life. You could have used that knowledge for good, but you've wasted your genius."

Don't worry, I can't really kill you in my current state, but of course I won't let you escape easily either.

There are still many things I want to ask you, and I'll make you tell me everything about the mysteries of this world.

As he spoke, Shirou glanced at Matou Sakura, who was hunched over not far away:

"But before that, we have to treat the pests in an environmentally friendly way."

Look, even your adorable granddaughter is scared by her grandfather's current appearance!

Shirou maintained his smile, his slender fingers toying with the brainworm's body like a mischievous child.

"what?"

"You want to 'live on,' right? Then let me grant your wish."

"You brat, what exactly do you intend to do to this old man!?"

Zouken Matou felt a chill run down his spine, and struggled even harder.

At this moment, Shirou Amamiya revealed a bright and innocent smile, which reminded him of the kind creatures that exist in fantasy—fairies.

"I want to help my ugly grandfather become someone his grandchildren will like."

As Shirou spoke, he pulled out something that left everyone speechless.

If the brain worm had eyes, they would probably be staring like flies by now.

"This is the new body (container) I prepared for you. Isn't it cute?"

What appeared in Shirou's hand was the little yellow duck that Matou Shinji loved most, floating in the bathtub.

"Do not--!"

Zouken Matou struggled desperately, but the boy held him firmly in his hand.

At the same time, Shirou began to perform magic.

Transferring the soul attached to a brain worm to another object and fixing it there is generally a very difficult sorcery.

The genius witch of Britain goes without saying, and it's an impossible task for the third-rate magician Shirou.

Fortunately, in order to facilitate repeated reincarnations and the continuation of its life, this old worm underwent a complete transformation.

The literal meaning of "to be trapped by one's own actions."

Although the soul is still uncontrollable, even Shirou can transfer the spirit without retaining the soul.

"Ah ah ah ah ah ah ah!!"

Zouken Matou felt himself being pulled out of the insect's body and screamed in panic.

He truly longed for eternal life.

However, it is ultimately about being a living being, and absolutely not about being an object!

What's more, this is a toy for people to play with in the bathtub!

If it's attached to an object with mystical properties, like a grimoire, at least it can maintain its rationality...

But it's just an ordinary toy rubber duck!

It has no history, no heritage, and no mystery whatsoever; it's just a little yellow duck that's like a grandson's toy!

Zouken Matou will definitely not hold back his true self... If this is the price he will pay forever, then he might as well just be slapped to death with a slipper!

"Stop, stop...you can't do this..."

Zouken Matou wailed in agony.

"You can't do this...you can't do this...!"

"I just genuinely want to help you achieve your wish of immortality, old man."

Shirou looked at him and sighed, "He's truly misunderstood no matter where he goes, the work of a savior."

...I was scammed.

I, Shinji, the daughter of the Tohsaka family... everyone was deceived by him!

Gentle? Composed? Hates evil? Full of justice and cannot tolerate wrongdoing?

That kid is not that kind of person at all!!!

Hidden beneath those layers of disguise is—

As a living being, Zouken Matou's final thoughts ended here.

The next instant, his soul vanished, and his spirit was forever imprisoned within the toy rubber duck.

From this day forward, Zouken Matou will no longer possess any sense of freedom or autonomy.

It can only be awakened when Shirou needs it and injects magic into the toy rubber duck.

Zouken Matou's current existence is quite similar to that of Ahadeon, the head of the Einzbern family, who is his ally.

An artificial intelligence with the personality of Zouken Matou, storing five hundred years of magical knowledge from the Renaissance to the modern era.

"Magic Terminal - Machiri".

Looking at the toy rubber duck in his hand, Shirou Amamiya had a satisfied expression on his face.

What is the one thing I lack most when I return to this world?

It's intelligence.

It is knowledge.

It is the perception of this world.