Fuyuki City

Magic Circuits are pseudo-nerves present within a Magus. They have two basic functions; one is to convert life force into magical energy and another is to allow their owner to access Thaumaturgical Foundations.

The number of Magic Circuits a person is born with is predetermined, and the purpose of Magus families is to produce offspring with even one more Magic Circuit.

Once opened, the Magus can freely activate these circuits. The talent of a Magus is often judged by the number of their Magic Circuits—for instance, Shirou Emiya has 27 Magic Circuits, while Rin Tohsaka has 40 main and 30 sub-magic circuits.

There are also some unique cases, such as the homunculi of the Einzbern family, who are created to serve as the core of the Holy Grail. After becoming the Grail, Justeaze's Magic Circuits expanded to a diameter of nearly one kilometre.

Another anomaly is those who bypass Magic Circuits altogether, using life force to perform magecraft directly—a path not to be proud of.

For Sakatsuki, this devastating revelation meant abandoning his carefree attitude. Instead, he had to proactively use his foresight and special abilities to prolong his declining lifespan.

After tearing apart the report, Sakatsuki forced Acht to sign a Geis contract. He then rode his Kawasaki Ninja H2R out of Einzbern Castle.

***

The night passed in silence.

Einzbern Castle has regained its former tranquillity, though now it houses a white-haired, golden-eyed young man who avidly absorbs centuries-old magical knowledge in the castle's library.

Illya continued to seek out Sakatsuki for playing, and he never refused her requests. Each time, he would reluctantly set his book aside, instructing her not to disturb him next time, while indulging her with his magecraft and accompanying Illya alongside Kiritsugu or Irisviel to watch her play, sharing in her joyous childhood.

Just like this seven days passed in a blink of an eye.

Now, the Fourth Holy Grail War was only a year away.

***

The following morning, dressed in a new suit and holding his motorcycle helmet, Sakatsuki bid farewell to the Emiya family.

"Are you leaving, brother Shirou?"

Illya clutched Sakuya's coat, her ruby eyes filled with reluctance.

"Can't you stay with me forever?"

Sakatsuki knelt, gently stroking Illya's hair as he did when they first met, his voice soft and distant.

"I can't. The destiny of a Kamen Rider is to wander the world."

"Brother Shirou is saying things I don't understand again."

Illya puffed her cheeks adorably, drawing smiles from everyone except Kiritsugu.

The Magus Killer's gaze was fixated on Sakuya's left hand, or more precisely, the black fingerless glove he had worn seven days ago and never once removed.

Could it be...

"Goodbye, Kiritsugu, Irisveil, and the lovely little princess. Although it's a pity I couldn't wait for that girl's arrival, I must continue my journey. Farewell, everyone."

Sakatsuki was not one to linger. After a brief farewell, he rode his motorcycle away from the snowy city.

"That girl...?"

Irisviel tilted her head in confusion.

"Will someone come to visit our castle?"

They couldn't understand that when that girl arrived, the fate of the Emiya family would meet its irreversible conclusion—unless Sakatsuki had never existed.

***

Annecy, France.

Annecy is one of the most beautiful towns in the Alps, known as the 'Balcony of the Alps' by the French and 'Venice of Savoy' by locals. It is said that the water of Annecy Lake, fed by the snowmelt of the Alps, is the cleanest in all of Europe.

Visiting Annecy, Sakatsuki had to explore its famed sites. By the lake, he met a young man from the East. After helping an elderly man whose wallet was stolen, they stuck up a conversation and became temporary companions.

"So, why are you here, Sakatsuki?"

The black-haired man in sportswear asked as he gazed at the shimmering lake.

"Just trying to enjoy my last moments before fate arrives."

Sakatsuki replied lazily, lying down on the grass, showing no sense of urgency.

"Wow, you're always talking about fate."

The man chuckled, playfully taking a jab at Sakatsuki.

"At your age, what's with the fate talk? Marriage jitters?"

"I'm not one to fear women."

Sakatsuki lazily glanced at him.

"Speaking of which, you were mumbling something about 'as long as Aoi is happy' and 'what's so great about Tokiomi Tohsaka' when drunk last night. Could it be... your crush ended up with someone else?"

Pausing, Sakatsuki spoke the man's name.

"Am I right, Kariya Matou?"

"Shut up!"

Kariya's teasing expression vanished, replaced by panic and embarrassment.

"I never said that! You must have misheard!"

"Sure, sure."

Sakatsuki dismissed the poor lie.

[005: Kariya Matou]

[Character Info: The second son of the Matou family, a descendant of Zouken, brother of Byakuya, and uncle to Shinji and Sakura. The only Matou descendent with slight magical aptitude among the Matou family's younger generation. In the original timeline, he was the Master of Berserker in the Fourth Holy Grail War. Zouken initially considered making Kariya his heir. During his youth he was introduced to Aoi Zenjou, daughter of the Zenjou magus family, to foster a connection.]

[Hidden Information: Unwilling to subject Aoi to the Matou family's grotesque worm magic, Kariya accepted Tokiomi's interference, severing ties with the Matou family and leaving on his own alone.]

[Record Conditions: None.]

"You punk, you just enjoy seeing me embarrassed!"

Kariya kicked Sakatsuki's leg in exasperation.

"You're catching a flight soon, right? Go already, stop teasing me."

Being kicked by his companion, Sakatsuki stood up reluctantly and suddenly asked.

"Why don't you return with me? Our routes match, after all."

"Fuyuki City... Huh!"

Pain and resistance flashed in Kariya's eyes before he shook his head.

"No, I'll leave in five days. I still need to buy some gifts for two little girls. I'll find you once I'm back."

"Gifts, huh..."

Sakatsuki chuckled lightly, casting a sympathetic glance at Kariya before donning his helmet and riding off.

"Hey! What's with that look?"

Kariya's protest faded behind him as Sakatsuki hummed a newly learned song, riding through the sunny town.

***

An hour later, a plane roared into the sky from Annecy airport, carrying weary and excited passengers and their unknown destinies.

Without interference from a Magus Killer wielding anti-aircraft missile, the plane took off and landed safely, eventually arriving on the runway of a western Japanese airport.

Minutes later, a mobile stairway connected to the exit door, which then opened.

A black-suited, dashing youth stepped off, stretching lazily as he gazed at the bright Fuyuki City.

On his left hand, revealed after removing his gloves, were three sigil-like marks.

These were Command Seals—a ticket to war.

***

Sorry, for not uploading new chapters these past few days, I was travelling these days and didn't have any time to write new chapters. But, don't worry as an apology gift I'll do a mass release in a few days.

Also, thank you for 40k views on the book.