Of course, achieving a good prep time requires an indispensable prerequisite—the situation in Fuyuki City must remain unchanged.
More accurately, the outside world must still perceive the Holy Grail War as a small-scale magical ritual in the Far East. The Clock Tower routinely sends two magus to go through the motions, and the Holy Church routinely dispatches a supervisor. Other than people like Kayneth, who rushes over on a whim looking for trouble, no major unrelated figures would typically come to participate.
However, if Shinji steps into the spotlight and becomes a well-known figure in the world of mystery, things could get complicated. As everyone knows, fame attracts attention, and along with it, people will dig into your background, experiences, and even the city you reside in. Although the Einzbern, Tohsaka, and Matou families have hidden the secrets of the Holy Grail War very well, there's no guarantee that this concealment can withstand the intelligence departments of the Mage's Association or the Holy Church.
If they discover something, they wouldn't need concrete evidence, just a certain level of suspicion. The situation of the Fifth Holy Grail War would then head into unknown territory. Not to mention, the two representatives decided by the Clock Tower for dispatch could become a significant variable.
Originally, the two Masters were a self-important, widely ridiculed nouveau riche called Atrum Galliasta, Master of Caster Medea. He angered Medea with his foolishness and was killed by his Servant. In the Fate series' original game, he doesn't even show his face until the latest UBW arc, where he gets a bit of screen time—such a first-class idiot is bound to self-destruct without any intervention.
The other is Bazett, recommended by the behind-the-scenes manipulator Kotomine Kirei, spanning across the Fourth and Fifth Wars. This woman is much more formidable than Atrum Galliasta. She is an ace enforcer of the Sealing Designation Enforcers, the Department of Spiritual Evocation, and the Astronomical Observatory, one of the few top fighters among the new generation at the Clock Tower. She can fight on par with combat-oriented Servants and possesses secret relics comparable to Noble Phantasms. Shinji remains cautious of her among the few.
However, this woman has a fatal flaw—she's too naive. With a bit of scheming, she can be tricked to the point of losing her way, the type who would help count the money after being sold. In the original timeline, she, like Atrum Galliasta, had no role in the main story. Before the story even began, she was schemed against by Kotomine Kirei, who recommended her, had her arm cut off, and lost her Command Seals and Servant—dealing with such a fool is as easy as pie.
But what if the Clock Tower knew this wasn't a small-scale magical ritual, but a ceremony to achieve the Third Magic? What if it could even reach the Root? What kind of participants would that colossal entity, which controls 90% of the magus in Western Europe, send? What heroes would they prepare to summon?
Look at the parallel world's Holy Grail War. The Sophia family, one of the Twelve Lords, prepared fragments of the Round Table and summoned top-tier catalysts like Karna and Achilles within days. Kayneth, no matter the world, always managed to get a piece of Iskandar's cloak. Lord Animusphere of the Astrology Department had one of the Ten Commandments worn by Solomon, the King of Magecraft.
Two beings on par with Gilgamesh and Karna, paired with Masters like Kiritsugu and Kairi, would make it uncertain whether Shinji could secure victory, even if he held onto his predetermined Master-Servant lineup. After all, there's no rule that Masters can't have helpers. Mercenaries, enforcers, a Brigade—any of these could cause more destruction than Kiritsugu and Maiya combined.
Moreover, can Shinji, or rather, the Three Families, truly hold onto their rightful participation slots? It was previously mentioned that these slots could be taken, either before or during the war. Compared to those colossal entities, the Three Families are still too weak.
The only fortunate thing is that during the Great Holy Grail's dormancy, no one can see its true nature. The Old Man of Jewels also promised to keep an eye on the matter, so Shinji isn't overly panicked. However, this concealment has its limits. The more active Shinji is the greater the variables.
Therefore, after confirming Touko's situation, Shinji quickly left the Tohno residence and headed to Hokkaido.
Leaving the Tohno residence was to avoid giving spies from various factions a chance to spot him, and going to Hokkaido was because Aoko Aozaki was currently there.
Shinji's goal wasn't to build a relationship with Aoko Aozaki. Given his current high-profile actions with Arcueid, if word got out that he was in contact with the Newest Magician, he might as well ask The Old Man of Jewels to move the Great Holy Grail. Trifas in Romania would be a good choice; Arcueid's castle, the Millennium Castle Brunestud, is there, and the Kazikli Bey can exert full power there.
Of course, Shinji would only choose this as a last resort. Romania is not like Japan; it is not within his sphere of influence. Moreover, the Mage's Association and the Holy Church have significant influence there and might monitor spiritual veins for anomalies.
Shinji came to Hokkaido to leverage Aoko Aozaki's deterrence.
That's right, deterrence. The Witch of Destruction is a notorious problem child among major factions, with an unpredictable personality and movements, disliking constraints and surveillance. Since her rise to fame, spies from all over the world have been severely beaten by her. Over time, an exclusion zone formed around Aoko Aozaki, and even if someone knew she was nearby, they wouldn't dare to scrutinize her too closely.
In Japan, besides those forbidden zones and secret realms, the areas around Aoko Aozaki are where spies act most cautiously. Thus, having recently made big news, Shinji Matou temporarily settled on the northern coast of the country, quietly observing the turbulent undercurrents in the outside world.
On the other side, Lorelei, Kayneth, and Zeretch also fulfilled their promises. Kayneth discreetly released various pieces of information, mixing truth with falsehood to confuse and mislead people about the Matou family's background.
Lorelei secretly dispatched two members of the Brigade to Fuyuki City to guard the Matou residence, handling spies in the shadows. She also sent a letter to the Matou family, describing Shinji's recent situation and issuing Matou Sakura's school admission notice.
Zelretch made the most brilliant move, appearing publicly at the Clock Tower and announcing his intention to take on a disciple. This attracted the entire world of mystery's attention, reasserting his presence and reminding many of a crucial fact—the Tohsaka family, the managers of Fuyuki City, was established by his disciple. Anyone planning to cause trouble in Fuyuki City should consider if they are tough enough.
This is truly a case of the magician taking charge, averting all misfortunes!