Shinji spoke.
He revealed to Artoria the truth about his transmigration and his unique nature.
It wasn't a spur-of-the-moment decision to create a big news story, nor was it a desperate move after learning Artoria's identity. It was because this was the best choice.
Artoria's character meant she wouldn't lie about such matters. If she said that the two great Counter Forces were paying attention to this Holy Grail War, it had to be true. Since the Counter Forces were paying attention, Shinji's identity as a transmigrator had surely been known to them.
From Artoria's behavior, it seemed the Counter Forces hadn't informed her about Shinji's background. But just because they hadn't told her now didn't mean they wouldn't in the future. Even if the Counter Forces remained silent from start to finish, the dream exchange between Master and Servant due to their contract could very well expose Shinji's background. After all, Scáthach had directly browsed through Shinji's past life via their contract, and Shinji had glimpsed through Scáthach's entire life.
In other words, Artoria would eventually learn about Shinji's background. Instead of waiting for it to be exposed later and potentially affecting their relationship, it was better to come clean now and show his openness, which could lower Artoria's guard.
Of course, Shinji had another option—like several Masters of Lancer before him, he could command Artoria to commit suicide. But this would be pointless. With the backing of the two great Counter Forces, Artoria might not be subject to Command Seals. Even if she did commit suicide, the Counter Forces could send another observer, or worse, deem Shinji a threat and send a Guardian to eliminate him.
Thus, Shinji made this seemingly foolish choice.
Unexpectedly, Artoria's reaction was unusually calm. Aside from a hint of surprise in her emerald eyes and a soft "Oh," she simply said, "So, Shinji, you're from a parallel world," with no other reaction.
Shinji felt a bit uncomfortable with this kind of Artoria. In his impression, she would react quite strongly to things she disagreed with, even if it involved someone close to her.
"Uh, why are you reacting like this? I'm uncertain factor, your mission target. Why aren't you nervous at all?"
"No, Shinji, you're mistaken." Artoria's ahoge swayed left and right as if nodding on her behalf. "I understand you're an uncertain factor, but you're not my target."
"Why do you say that?" Shinji didn't understand.
Artoria countered, "It's simple. Do you have the capability to pose a significant threat to humanity or the planet?"
"No," Shinji realized.
Indeed, among the beings on Earth, Shinji was quite strong, but compared to the planet itself and all of humanity, he was insignificant. Even if he obtained the Holy Grail, he didn't have the power to alarm the Counter Forces. Moreover, he had no intention of harming the planet or humanity; he would certainly stand against anyone who tried.
"So, you're not my target," Artoria confirmed. "Not only that, but you'll also assist me. My intuition tells me so."
"Thank you for your trust—if it's not me, then who could it be?"
As Shinji muttered to himself, he pondered.
First, he ruled out the Yggdmillennia Masters. Neither their strength nor their objectives were noteworthy.
So, it had to be someone from the Red Faction. There were seven Masters from the Red side.
Kairi Sisigou was essentially no different from the Yggdmillennia group and could be ignored.
The remaining six Masters... even Shinji, with his deep knowledge and dedication to the series, couldn't remember their names.
In "Fate/Apocrypha," these five Masters were tragic characters who only had names and a few lines, with no detailed descriptions (they were slightly better in the anime and manga, where they at least had faces).
Although the setting described these five as renowned combat magi in the mystic world, they were manipulated by the final Master of the Red Faction before they could showcase their abilities, rendering them background characters.
So, it's the mastermind behind this Holy Grail War, the final Master of the Red Faction—Kotomine Shirou, or rather, Amakusa Shirou. It's not impossible that he caught the attention of the Counter Forces.
His wish through the Holy Grail was to save all of humanity, intending to use the Grail to trigger a miracle that would render all of humanity immortal, thereby eliminating war and achieving world peace. He had been plotting this for over sixty years, meticulously preparing and calculating almost every factor. If all went according to plan, humanity would soon be redefined.
Although he didn't aim to destroy humanity directly, the act of changing the fundamental nature of human existence carried enormous risks. No one could predict whether humanity would thrive or perish if they became immortal. This uncertainty was enough to alert Alaya.
Transforming the nature of all humanity would require an unimaginable amount of magical energy, possibly draining the world's ley lines dry. This would have a massive impact on the Earth, likely catching Gaia's attention as well.
In "Fate/Apocrypha," the protagonist Sieg's ability to thwart Amakusa Shirou was perhaps due to the Counter Forces' covert assistance. Otherwise, how could a newly created homunculus like Sieg survive countless life-threatening situations and eventually defeat the overwhelmingly powerful Amakusa Shirou?
This time, due to his intervention, Sieg's various opportunities were bound to be affected. Thus, the Counter Forces changed their strategy, sending Artoria instead, and his assistance to Artoria was also within their calculations. Perhaps even Vlad III's shift from Lancer to Berserker was influenced by the Counter Forces to allow Artoria to materialize in the Lancer class.
In this class, Artoria might not possess the renowned Excalibur, but she had an even more powerful Noble Phantasm. This Noble Phantasm symbolized the protection of humanity, making it perfect for countering Amakusa Shirou, who intended to subvert human nature.
With this understanding, everything made sense. But why did he still feel something was off? What other factors had he not considered? Those five unnamed Masters?
"Shinji, Shinji? Have you thought of something?" Artoria asked, noticing her Master's increasingly furrowed brow.
"I have some ideas, but they're not fully formed. We should proceed with the Holy Grail War as planned and draw conclusions once we have enough information."
Shinji chose not to reveal all his thoughts, as they were based on his knowledge of "Fate/Apocrypha," which was hard to explain and not guaranteed to be accurate. However, this wouldn't stop him from making a promise to the Knight King he had admired for the past ten years.
"Artoria, no matter who your ultimate target is, I will stand by your side and fight alongside you."
"By the name of a knight, I promise I will help you obtain the Holy Grail!"
Artoria's expression was solemn. This was the belief of a knight, the vow of a knight, whose firmness and resoluteness overshadowed everything.
PS: If the very nature of human existence is changed, isn't that a subversion of human principles?