Fate: Hero of Justice Takeover

Let's start with a man.

A man filled with ideals more than anyone else, yet driven to despair because of them.

His dream was simple.

He sincerely wished for everyone to be happy.

Every boy has harboured such dreams, but they abandon them when they understand the harshness of reality, deeming such ideals childish.

Happiness comes at the cost of sacrifice—this is a lesson everyone learns as they grow up.

But this man was different.

When he realized that all life in this world is balanced on the scales of sacrifice and salvation and that it is impossible to clear either side completely...

He decided to become the master of the scales.

***

In the snow-covered forest, a small passage had been made in the defensive barrier, enough for someone to sneak into the Winter Castle undetected.

...That is if the infiltrator had a map.

Unfortunately, Sakatsuki didn't have such a thing, so he chose a simple and crude method—following the trajectory of the ley lines.

As the base of the Einzbern family, the Winter Castle was naturally built on the best leylines in the Alps, a common knowledge among the magus families.

Thus, by following the ley lines, he would eventually reach the core of the castle.

Amid the snowstorm, Sakatsuki used Displacement magic to swap and disrupt the alert functions of the defensive magic array, dismantling the mystery as if breaking apart building blocks, feeling somewhat smug.

As an ordinary person from a normal world just half a month ago, he was quite satisfied with his decisions.

However, the result of his proud actions ended up in an unexpected failure.

Crunch! Crunch!

The sound of little snow boots struggling through the thick snow, small hands pushed aside the bushes, and a little girl wearing a purple felt hat and a purple dress curiously looked around, slowly approaching Sakatsuki's location.

If it weren't for the heavy snow affecting visibility today, she might have spotted the intruder, Sakatsuki, immediately.

Damn, big mistake.

Sakatsuki silently reflected as he watched the small figure walk towards him.

He had considered every magical variable but failed to account for the possibility of being discovered by someone.

There was still a chance to escape though, if he withdrew before being noticed, he could avoid the Bad End of a failed infiltration.

Yes, with speed beyond the ordinary humans, he could surely leave gracefully.

But as he was about to act, the face of the approaching girl stopped him as if he had lost power in his body.

The blood in his body seemed to flow in reverse, trembling with excitement as unfamiliar emotions coursed through him, forcing Sakatsuki to stare at the small figure walking towards him.

Silver hair, ruby-like eyes, a purple dress. She looked just like a fairy.

All these features pulled a single name from Sakatsuki's mind, from within Shirou Emiya's body—

Illyasviel von Einzbern.

The child of his adoptive father, Kiritsugu Emiya, and wife, Irisviel von Einzbern, and also his, Shirou Emiya's, adoptive sister—though Sakatsuki was taller and older than her by a considerable margin.

Perhaps due to the memories of the original host, even when facing a family member from a different worldline, he felt an intense sense of joy. As if someone who had nothing realized they were not alone on their wandering journey.

At this moment, Illya finally noticed the unfamiliar big brother standing in the snow.

Without alertness or shouting, the silver-haired girl gazed at the tall white-haired young man with a look of surprise and smiled.

Although she was only six years old and barely able to stand, Illya still curtsied in a lady-like manner, then eagerly stood up, her ruby eyes full of anticipation.

"Big brother, big brother, do you know what walnut sprouts are?"

Under Illya's expectant gaze, Sakatsuki couldn't bring himself to say "no" and could only smile wryly as he crouched down.

"Yes, I do. They are the new buds growing out of walnut trees, right?"

"Yes, yes!"

Illya smiled happily upon hearing the affirmation.

"Hey, big brother, could you do me a favour?"

"Of course, go ahead."

"Help me find walnut sprouts in the forest!"

Illya clenched her little fists and said with determination.

"I must beat Kiritsugu in tomorrow's competition!"

So, it was the reason for today's sneaky outing? No wonder no one else was with her... Shuyue thought for a moment and then smiled as he extended his hand.

"It would be my honour, Princess of the Winter Castle."

However, his gesture seemed to have been misunderstood by Illya, who happily grabbed his arm, climbing up like scaling a mountain while saying "Heave-ho, Heave-ho."

Sakatsuki wavered slightly but quickly stabilized himself.

The petite, frail body of the girl wasn't as heavy as Sakatsuki had anticipated. Holding her felt like scooping up fresh snow, so delicate and fragile.

She weighs less than fifteen kilograms... Sakatsuki quickly concluded.

Inherited magical knowledge from the Einsworths coldly assessed. This girl's body had long been altered, resembling more a vessel for some artefact than a human. Her growth would likely cease during early puberty.

Illyasviel... She embodied the culmination of a millennium of the Einzbern family's achievements, as well as their accumulated sins.

"Let's go, big brother!"

Illya, unaware of Sakatsuki's thoughts, quickly adjusted herself on his shoulders, catching her breath before excitedly shouting.

"I'll beat Kiritsugu tomorrow!"

Breaking out of his chaotic thoughts, Sakatsuki displayed a gentle smile to Illya.

"At your service, my most adorable little princess."

"Wow, so high! Illya is flying...!"

The clear, carefree laughter of a child echoed through the snow-filled walnut forest.

"Big brother, what's your name?"

"Saka... no, just call me Shirou. At least here, you can call me that."

"Oh... so, big brother Shirou, have you found any walnut sprouts?"

"Look over there, are those walnut sprouts?"

With his inherent skill [Clairvoyance: C], Sakatsuki could see the sprouts wrapped in snow clearly.

"Where, where? Wow, they really are walnut sprouts! Big brother Shirou, you're amazing!"

"Haha! Of course, I am."

Amid the laughter, Sakatsuki and Illya slowly traversed the forest, with the magnificent silhouette of the Einzbern family's castle becoming faintly visible in the distance.

"So this is Winter Castle..."

Sakatsuki's sigh of unfamiliarity caught Illya's attention, her seven-year-old mind finally making sense of the situation.

"Wait... does this mean, that big brother Shirou isn't a member of the Einzbern family?"

The snow in the forest seemed to fall heavier, and after a moment, the Sakatsuki's pleasant laughter rang out.

"You caught on quickly, Illya. You're smart."

"Of course, Illya is very smart!"

The little girl sitting on Sakatsuki's shoulders proudly put her hands on her hips, soon asking curiously.

"I heard Kiritsugu say that magi outside the castle can perform magic. What about you, big brother? Can you throw fireballs? Or make a potion that turns into a rabbit when you throw a bunch of stuff into a pot like Kiritsugu said?"

Seemingly not expecting it to go this far, Sakatsuki paused for a moment before letting out a laugh.

"Hahaha... My princess, really, perhaps the entire Einzbern family should be grateful that you were the first to meet me."

"???"

The little girl tilted her head, her small head filled with multiple question marks.

But Sakatsuki's gaze wasn't on her; instead, he looked up at the snow-laden sky, as if talking to himself.

"Illya, don't you think today's weather is too bad?"

"Big brother Shirou really doesn't live here, does he? It always snows here, but Kiritsugu said the weather would improve tomorrow?"

"No need to wait until tomorrow."

"...Huh?"

Illya froze, and in the next moment, a cold, piercing aura emanated from beneath her.

It was a sensation she was very familiar with, something Kiritsugu called mana, but even she had never witnessed such a massive surge of magical energy.

"Watch closely, Illya."

Sakatsuki narrowed his golden eyes. The overwhelming magical energy surged out, transforming into a dazzling magic circle that enveloped the entire forest.

"This is one of the magics I possess."

The wind ceased.

The snow stopped falling.

The sky turned milky white.

Sunlight streamed down from the clear sky.

"Wow..."

Illya gazed at the suddenly brightened sky, exclaiming in disbelief.

In her innocent little head, only one thought echoed.

With this, she could look for walnut buds in the forest with Kiritsugu every day!

***

According to later reports by the German Meteorological Service, within a ten-mile radius centred on a certain spot in the Alps, the snowstorm that was supposed to continue until the next day abruptly cleared, while in contrast, heavy snow suddenly began to fall in the distant town of Lauterbrunnen.

It was as if an invisible hand of God had swapped the weather of the two places.

Later, this report was archived by the Mage's Association, the Clock Tower's Sealing Designation Bureau, with the assistance of the Holy Church, preventing massive panic in the modern world due to this weather anomaly.

Of course, that's a story for another time.