Shinji Matou at Your Service

"Land of Steel."

An incredibly heavy name.

A world where living beings cannot survive.

It is not an official name but a colloquial term commonly used among the "people" who live on the desolate earth, referring to the dying star, the Earth about to perish, and the complete end of the century.

As the name Land of Steel suggests, most of the continent is now a cracked wasteland, covered by gray and white clouds. Food cannot be grown, and the atmosphere is no longer suitable for animal life as it once was.

Yes, this is the distant future, the end of the Earth.

In a sense, a planet is also a kind of life form, and though its lifespan is incomparably long compared to short-lived humans, it will eventually face death.

The Earth is dying, and Gaia, the counterforce, is also disappearing. Before its disappearance, it called upon its peers, the U.O. from other planets in the solar system, to extinguish all life on the planet.

U.O., short for Ultimate One, are the strongest life forms on each planet, each possessing the terrifying ability to wipe out all life forms in the existing world single-handedly. They have no concept of names and are named by the surviving humans, just like Land of Steel.

Indeed, even at the end of the planet, humanity could not be exterminated. They still survived relying on advanced civilization technology. This also means that the long-standing balance and struggle between the two counterforces, Gaia and Alaya, finally came to an end, with Alaya emerging victorious.

However, this came at an incredibly heavy cost. The mother planet died, the ecological environment completely changed, and human civilization was severely damaged, barely surviving on the dying earth, living every day under the threat of U.O.

Undoubtedly, this is an extremely disastrous ending.

Moreover, it is an ending that all parallel worlds will inevitably face—great beings such as the Old Man of the Jewels and the Night of Wallachia have foreseen this ending.

The Night of Wallachia continuously calculated to avoid this ending but could not find an answer despite all efforts, ultimately pinning hopes on the legendary Sixth Magic, becoming a vampire.

The Old Man of the Jewels is the same. In his view, although a method to avoid it has not been found, that ending can certainly be avoided. The reason is simple: among the nine planets of the solar system (currently, it is 1999, and Pluto has not been excluded yet), Earth is not the oldest and is not dying a natural death. Since it is not a natural death, there is a possibility of avoidance.

To this end, he used the second magic, Parallel World Interference, to constantly traverse world lines, conducting various experiments. Countless failures, countless summaries, countless restarts—the accumulated data and experiment reports could fill an entire library.

A traveler named Shirou, whom he met during his journeys through parallel worlds, and another traveler now named Shinji Matou, were among his test subjects, with Shinji being a particularly special one.

"Because you and I come from the same place?"

After hearing Shirou's explanation, Shinji pondered.

"That is only a part of it. To be precise, you are from outside the Type-Moon universe but within the concept of Earth. The former makes you an unpredictable variable—with a variable, the ending can change, whether for better or worse. The worst thing is an unchanging outcome. The latter ensures that you can seamlessly integrate into Earth without being rejected as a 'foreigner.' You don't need to delve into the specifics for now, as I've only uncovered the tip of the iceberg of the multiverse myself."

"I understand, don't touch on things beyond my reach—just tell me what I need to know."

This answer made Shirou very satisfied.

"With this attitude, I can rest assured. The old man of the jewels didn't throw you into that special world line in vain."

"A special world line? Like Justeaze's survival?"

"That's just one of the special elements. There are many other special factors. For example, Dead Apostles and Servants. Dead Apostles are enemies of humanity, while Heroic Spirits are protectors of humanity, and they are mutually antagonistic. Therefore, in a world line where the 'Servant Summoning' system prevails, the power of the Dead Apostles weakens. In the world line of 'Fate/Zero,' the power of the Dead Apostles is far inferior to that in the world line of 'Tsukihime,' and the list of the twenty-seven ancestors is different. Most importantly, Roa, the origin of the Tsukihime story, was also wiped out by Edmond Dantès during his lifetime."

"What? There's such a setting?"

Shinji was stunned. "So, if I send Touko Aozaki to the Tohno family to find Roa, wouldn't she come up empty-handed?"

"Didn't I say? The world line you're in is special. It's like a test tube, with all the elements that the old man of the jewels and I could add, whether from Tsukihime or the Fate series, so Roa still exists."

"I see..."

"By the way, there's something I need to remind you—although various elements have been successfully blended, it's still not the original world line, and with you as a variable, I don't know what changes will occur in the future."

"Don't you have access to the Mooncell? How could you not know?"

"After that world line took shape, I stopped observing it. Since it's a man-made world line, it's not as stable as a typical one. Even just observing it could have adverse effects because of my significant presence as a super variable."

"Then is there no problem with this world line?"

"No problem, because it's a normally derived world line."

Shirou sighed helplessly.

"But now, over seventy percent of my body is composed of alien elements. In the Type-Moon world, which is exclusionary to outsiders, my true form would be jointly attacked by the two counterforces as soon as it appeared. This is the only way I can enter Earth."

"That doesn't sound like a good way."

Shinji pondered.

"Of course not. Replacing the existence of a Servant isn't easy. Servants are Heroic Spirits renowned in human history, and even with Mooncell's power, it's difficult to interfere. First, there has to be compatibility, and second, the Heroic Spirit must cooperate willingly."

"Willingly?"

Shinji was surprised. Amakusa Shirou Tokisada's will was incredibly strong, so he was willing to be replaced?

"How did you manage that?"

Shirou laughed mischievously, like a weasel that had successfully eaten a chicken: "I showed him 'Fate/Apocrypha'—the adapted version. Then I told him that with the counterforce in place, he couldn't succeed, but if I took over, there might be a slight chance."

"You're ruthless!"

Shinji was convinced, completely convinced.

Amakusa would do anything to save humanity, including sacrificing his own life. He chose Semiramis as his Servant, fully prepared to become her puppet. It wasn't hard to guess what choice he would make once he knew his wish couldn't be fulfilled.

"But even after giving up his existence, his obsession remained within the Spirit Origin, constantly reminding me to seize the Greater Grail and save humanity. Especially after I hid the Greater Grail, that obsession almost drove me crazy, forcing me to make that wish. Truly, he was a saint who could endure for sixty years. Just for that, I raise a toast to him!"

"A toast to Amakusa Shirou Tokisada!"

Regardless of whether his wish was right or wrong, his sheer persistence and the sacrifices he made for it deserve respect.