However, what Shirou Amamiya had done was the complete opposite of an explosion.
He had only wanted to delay the enemy, not blow the entire mansion sky-high, so he had been extremely particular about the amount and placement of the explosives.
Using bombs underground without affecting the buildings aboveground at all—this was clearly an explosive technique even more sophisticated than demolition.
Of course, it was also one of the techniques he had mastered in Britain.
"Grrr! Damn it...!"
A few seconds later, Zouken Matou crawled out of the rubble, covered in dust.
He could not understand how Shirou had infiltrated the place tonight, evaded the Blade-Winged Worms' surveillance, and planted the explosives all at the same time.
Of course, he could never have imagined it.
Because the explosives had not been planted tonight.
Much earlier—
On the first day after moving into the Matou Residence.
When Shirou had secretly slipped out at night to inspect this workshop, he had "casually" left the worm user a small gift.
A magic workshop was a magus's domain.
A magus inside his own workshop was invincible, so Shirou had determined that if he were to fight Zouken Matou, he would have to stay as far away from that workshop as possible.
The explosives had originally only been prepared as a precaution. He had never expected them to actually come in handy.
Elsewhere.
After being toyed with unilaterally again and again, Zouken Matou's rage reached its peak.
His hunched body trembled continuously as the worms inside him writhed. He glared furiously at the two people ahead—
"?"
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 already too late.
"Swish!"
Shirou emerged from the darkness behind the old magus and swung his blade at his neck.
Zouken Matou's head flew off and rolled aside with a "clatter."
Having landed the first blow, Shirou pressed his advantage. His second slash came diagonally down from the left shoulder.
"Riiip!"
The blade passed cleanly through the body. Had the monster that had ruled the Matou Family for centuries really been cut in two without putting up any resistance...?
In an instant, the old man's tiny body transformed into an endless swarm of Blade-Winged Worms, surging toward the red-haired youth like a black storm!
"Brother Shirou!"
Sakura Matou cried out in alarm at the sight.
As expected, ordinary physical attacks inflicted extremely limited damage on Zouken Matou.
Shirou remained calm and unhurried, as though he had anticipated all of this long ago.
He allowed the worms to gnaw at his skin, released the chain blade with his right hand, and thrust it directly into the depths of the swarm.
He seemed to be searching for something. Then he caught one of the worms.
"Ah, found you."
"Hissss!"
In an instant, the swarm biting at the young man stopped moving, as if someone had pressed a pause button.
Although Zouken Matou's body was tiny, it stored a massive number of worms—more than a thousand of them—covering the surrounding area densely.
Yet Shirou had instantly found the swarm's leader among nearly a thousand worms: the sole Brain Worm bearing Zouken Matou's consciousness.
It was a skill bordering on the miraculous.
On one hand, it was thanks to the continued effect of the Boundless Mage's Eye he possessed. On the other, it came from the keen insight he had honed through countless battles—Clairvoyance (True).
Within Zouken Matou's "life system," the Brain Worm served as the central nervous system, but it had no corresponding means of counterattack. After all, he had never imagined that his true body would be captured alive.
Thus, Shirou only needed to inject a little magical energy into the Brain Worm before using a simple spell to seize control of the swarm.
"Good. Let's try giving an order—"
The red-haired youth calmly spoke as he tore the wings off Zouken Matou—the Brain Worm.
"Every worm except the old man... commit suicide."
Crackle, crackle...
A black rain of worms fell through the underground passage. In an instant, the shattered remains covered the floor.
The first battle after his return had ended just like that.
Volume One 011: True Nature
"Is this the true body?"
Shirou examined the Brain Worm writhing in his hand.
The little thing was rather cute.
"Guh... kill me!"
The Brain Worm clearly had no vocal organs, yet it let out a shrill, comical cry like a defeated female knight.
"I refuse."
Shirou immediately saw through Zouken Matou's lie, as well as the mystery behind his immortality.
"Just as I expected. The moment one body is killed, you transfer to the next worm—the next vessel... You set up a spell like that? Hmph. I won't fall for it."
The old magus's ugly and feeble form was reflected in his amber eyes.
Even Zouken Matou would waver when he saw his own revolting original form.
Shirou sensed the emotional fluctuations of the worm in his hand, but paid them no mind. In an utterly calm voice, he spoke words that drove Zouken Matou gradually toward despair.
"You certainly went to great lengths to preserve your life. What a waste of your genius mind—you could have used it for something worthwhile.
"Don't worry. With my current strength, I can't truly kill you. Of course, I won't let you escape easily, either.
"There are still plenty of things I want to ask you. As for information about this world's supernatural side, I'll make you spit out every last detail."
As he spoke, Shirou glanced at Sakura Matou, who had drawn her shoulders inward in the distance.
"But before that, I need to make this pest harmless.
"Look. Your adorable granddaughter is frightened by what her grandfather looks like now."
Shirou kept smiling as his slender fingers toyed wantonly with the Brain Worm's body like a mischievous child.
"What?"
"Don't you want to 'stay alive'? Let me fulfill your wish."
"Y-you brat, what are you planning... What are you going to do to me!?"
Zouken Matou felt a bone-deep terror and began struggling even more desperately.
At that moment, Shirou Amamiya revealed a bright, innocent smile that reminded him of the kind creatures found in fantasy—the fairies.
"I'm going to turn the ugly grandfather into something his grandchildren will like."
As he spoke, Shirou pulled out something utterly astounding.
If the Brain Worm had eyes, they probably would have bulged like a fly's right now.
"This is the new body—the new vessel—I prepared for you. Cute, isn't it?"
What appeared in Shirou's hand was Shinji Matou's favorite toy: a Little Yellow Duck floating in the bathtub.
"No—!"
Zouken Matou writhed with all his might, but the youth held him firmly in his hand.
At the same time, Shirou began casting a spell.
Transferring the soul attached to the Brain Worm into another object and fixing it there was normally an extremely difficult form of magecraft.
The genius witch of Britain went without saying, but for a third-rate magus like Shirou, it should have been an impossible task.
Fortunately, this old worm had thoroughly modified himself so that he could reincarnate and prolong his life again and again with ease.
The literal meaning of being trapped in a cocoon of his own making.
Although the soul itself could not yet be manipulated, transferring only the mind without preserving the soul was something even Shirou could accomplish.
"Ahhhhhhh!"
Zouken Matou felt himself being dragged out of the worm's body and screamed in panic.
He had indeed yearned for eternal life more than anything.
But fundamentally, he had yearned for it as a living creature, and absolutely not as an object!
What was more, this was a toy meant for splashing around in a bathtub!
If he were attached to an object possessing mystery, such as a Grimoire, he could at least retain his rationality...
But this was merely an ordinary Little Yellow Duck!
It had neither history nor legacy, and not the slightest trace of mystery. It was just his grandson's toy Little Yellow Duck!
Zouken Matou would certainly be unable to retain his sense of self... If that was the price of eternity, he would rather be beaten to death with a slipper!
"St-stop... You can't do this..."
Zouken Matou wailed in agony.
"You can't do this... You can't!"
"I only sincerely want to help you fulfill your wish for immortality, old man."
Shirou watched him and sighed. "No matter where I go, no one ever understands me. The work of a savior is truly difficult."
...He had been deceived.
The old man, Shinji, the daughter of the Tohsaka Family... Every one of them had been deceived by him!
Gentle? Steady? Hating evil? Filled with a sense of justice and unable to stand wrongdoing?
The brat was nothing like that at all!!!
Hidden beneath layer upon layer of disguise was—
As a living being, Zouken Matou's final thought ended there.
In the next moment, his soul vanished, while his mind was eternally imprisoned inside the toy Little Yellow Duck.
From then on, Zouken Matou would possess neither freedom nor an independent consciousness.
Only when Shirou needed to use him and injected magical energy into the toy Little Yellow Duck could he be awakened.
The current existence of Zouken Matou was, in some ways, extremely similar to that of his ally, the head of the Einzbern Family, Ahadon.
An artificial intelligence storing five hundred years of magecraft knowledge from the Renaissance to the modern era, with the personality of Zouken Matou—
"Magic Terminal Makiri."
Looking at the toy Little Yellow Duck in his hand, Shirou Amamiya wore a satisfied expression.
After returning to this world, what did he lack the most?
Information.
Knowledge.
An understanding of this world.
Before you continue