His thoughts involuntarily drifted back to last night, deep underground in the Matou estate that reeked of rot.
Zouken Matou, his father—that centuries-old monster—stood at the edge of the worm pit, leaning heavily on his cane.
A twisted smile hung on his face.
The smile was so deep and forced that the corners of his mouth nearly split to his ears, exposing his yellowed gums.
Amidst his eerie laughter, he tossed a seemingly tattered piece of black cloth in front of him, one that emanated an overwhelming stench of death.
"Kariya, my good boy, since you are so determined to throw your life away for that little girl from the Tohsaka family, I shall show you mercy and grant you a miracle," he rasped.
"Use this cloth as a catalyst... This is a fragment of a higher-dimensional being, something I collected after an unbelievable journey."
"Although it does not belong to any myth of this world, the power it contains is enough to crush any enemy."
"Go, summon that 'God of Death' imprisoned within the rift of spacetime. Although your aptitude is so poor that he may not be able to manifest in one of the Three Knight Classes, it will be more than enough to defeat them all."
Following the incantation of the spell, that monster was born.
Kariya still remembered how, the moment that katana-wielding Heroic Spirit appeared in the center of the summoning circle, the entire swarm of worms in the Matou estate froze instantly.
It was an absolute suppression from the depths of the soul, instilling the most primal fear in all living creatures.
"Hey, can you hear me?"
Kariya shouted at the silent figure's back, his voice echoing across the empty beach.
"No matter who you are... no matter which myth's God of Death you once were, since you answered my summons, lend me your power."
The Heroic Spirit did not turn around.
"We have to win, we absolutely must win!"
Kariya's emotions suddenly flared, his half-disfigured face looking twisted and grotesque under the moonlight.
"I have to save her... That child shouldn't be left in that hell! She's only six years old!"
"She should be running in the sunlight, acting spoiled in her mother's arms... not having those disgusting worms burrow into her body, treated as a mere tool by that old bastard!"
Sakura Matou, or rather Sakura Tohsaka, was Tokiomi Tohsaka's second daughter.
Once upon a time, Kariya's greatest joy was taking Sakura and Rin to play in the park, watching their mother—
Aoi Tohsaka, the woman he loved most in his life yet could never have, smiling gently from the sidelines.
But all of that was personally destroyed by Tokiomi Tohsaka a year ago.
"The bloodline of a magus... Heh, what a curse."
Kariya laughed self-deprecatingly, his voice sounding exceptionally desolate.
In the world of magi, if a family birthed two highly talented children at the same time, it was not necessarily a good thing.
Because a magus's Magic Crest could only be passed down to one person. The other child with exceptionally high aptitude, if lacking the protection of a major family, would often receive a Sealing Designation from the Mage's Association.
They would either have their Magic Circuits ripped away or become a specimen locked in a jar of formalin.
To protect his daughter and to ensure her outstanding aptitude did not go to waste, Tokiomi Tohsaka accepted the Matou family's proposal and adopted Sakura into the Matou family.
But he had no idea that the Matou family had long since rotted away.
That centuries-old monster, Zouken Matou, had no intention of raising an heir.
He merely wanted an excellent vessel.
Thinking of Sakura Matou's hollow, despairing eyes in the worm pit, with tens of thousands of Crest Worms burrowing in and out of her skin, forcibly modifying her body...
Kariya's heart ached as if it had been seared by a red-hot iron.
That agony was a thousand, ten thousand times worse than the gnawing of the Crest Worms inside his own body.
He felt as though he could read the despair in the girl's eyes.
To save Sakura, he bowed his head to Zouken, accepting the implantation of a massive number of life-draining Crest Worms into his body to forcibly obtain the qualifications of a Master...
"Tokiomi Tohsaka... you arrogant bastard... you pushed Sakura into hell with your own hands!"
Kariya Matou clawed at his own scalp in agony, nearly shattering his teeth from gritting them so hard.
"You sit in that magnificent mansion, sipping red wine and discussing the Holy Grail, completely ignorant of the suffering Sakura is enduring!"
"I will punish you! I will make you watch everything you cherish be destroyed, and I will make you kneel before Sakura and repent!"
"Even if my soul is burned to ashes, even if I become an evil demon of hell... I will not hesitate!"
He had to win the Holy Grail!
As long as he won the Holy Grail, Sakura would be free! As long as he won the Holy Grail, he could kill Tokiomi Tohsaka with his own hands!
Amidst this frantic venting, the perpetually silent Berserker finally moved.
Turning his head slightly, two cold gleams of light seemed to flash within the shadows beneath his bone mask.
He still did not speak.
Under the influence of his Madness Enhancement attribute, he had already lost the ability to communicate rationally. Maintaining such calmness was already a feat in itself.
But he seemed to understand Kariya's obsession.
The long sword in his hand swayed slightly, and a black cyclone enveloped the moisture in the air, cheering within his grasp.
Then, under Kariya's shocked gaze—
He released his Noble Phantasm.
The long sword transformed into a pitch-black trident, surging endlessly with water-elemental magical energy.
It felt as though a full-powered strike from him could bury the entirety of Fuyuki City.
What rank of Noble Phantasm was this? Kariya could not even begin to judge.
He clenched his fists, revealing a miserable smile.
"Good... exactly like this," he muttered.
"This power... this despair... we must bring it to that man."
Meanwhile, Asuka, who was currently instructing Sumire Kamado in her sword-swinging training, shuddered the very instant that Berserker released his Noble Phantasm.
By the windowsill, Sumire Kamado was slumped over the railing, drenched in sweat and coughing violently.
"I can't do it anymore... Mr. Asuka... my lungs are really going to explode..."
The young girl's fair face was flushed red, her chest heaving heavily.
But she noticed that Asuka did not respond.
His spiritual body had already phased out of the room and moved to the roof.
'Whose Spiritual Pressure is this? How is this possible?' he thought, looking uneasily toward the coast.
Although he still wasn't sure if Reiryoku and magical energy were completely equivalent, this sensation was far too familiar.
'It's weaker than the aura on Urahara, but still incredibly formidable... Are the Heroic Spirits of this world equivalent to Captain-class powerhouses?'
He suddenly felt a bit uncertain.
If it were purely based on raw strength, even if a true Captain-class fighter arrived, he would dare to exchange a few blows to test the waters.
But the problem was his current level of strength...
Asuka looked down at the panting Sumire Kamado and frowned.
'Is there any way to increase her magical energy reserves...?'
Asuka floated back into the room, lightly resting his ethereal hand on Sumire's back, guiding the chaotic magical energy within her body to flow smoothly.
"What I'm going to teach you now is the training method I used when I was still human," he explained gently.
"I'm not sure if it will work, but we might as well give it a shot."
"Now, feel the magical energy in the atmosphere... it's the same special power that resides within your body..."
"Imagine them as naturally existing particles. Then, expand your lungs and integrate this magical energy into your bloodstream..."
Asuka's voice was incredibly patient.
What he didn't know was that whether this training method worked or not didn't entirely depend on Sumire Kamado.
Rather, it depended more on the wish within his own heart.