"Of course there's evidence. Whether you choose to believe it is up to you," Morgan said calmly. "The day after I was summoned, once the Holy Grail War began, I accompanied my Master to survey the situation in Fuyuki, which led me to discover the location of the Greater Grail."
Ryuudou Temple, atop Mount Enzō.
Back then, the Tohsaka, Makiri, and Einzbern families had established the system of the Greater Grail under the supervision of Wizard Marshal Schweinorg, refining it with each successive Holy Grail War.
Its location had long become an open secret among Masters.
Given that Morgan was summoned under the Berserker class, it made perfect tactical sense for Shiomi to bring her to investigate the spirit veins—and the Greater Grail itself.
"So, Lady Witch, you actually entered the underground chamber where the Greater Grail is stored and verified the system?" Tokiomi asked, clearly concerned.
Morgan nodded, then added deliberately, "Originally, I only intended to use the spiritual grounds of Ryuudou Temple as a base once the war reached its midpoint, but—"
"You discovered the Grail had been corrupted?" Artoria interjected.
She couldn't accept the idea that the wish-granting vessel she had answered the summons for was no longer pure.
"Exactly. The mana within the Greater Grail has been tainted. Whether used as a wish-granting device or for any other function, it's no longer viable," Morgan replied with composure.
She had already fully analyzed the Grail's system. Given time, she could even construct a replacement—one less costly, even.
"They're nothing more than broken tools now," she added.
"Broken?" Artoria's composure began to falter. She shut her eyes, forcing herself to ask, "What do you mean by that?"
"In short, the means by which it fulfills wishes have become extremely twisted and dangerous," Morgan said, turning to face her. "Didn't you wish to use the Grail to prevent the downfall of Britannia? If you offered that wish to this corrupted Grail, it would attempt to rewrite established history itself—because only by overturning recorded human history could the fall of Britannia be undone."
Cold sweat beaded on Artoria's cheeks. "If it did that..."
"If it did that, Britannia would be severed from the rest of the timeline—turned into a foreign object, a distortion of human history…"
At that point, Morgan's voice grew slightly heavier. Only Shiomi noticed, as everyone else remained fixated on the topic of the Grail.
"In other words, it would become a Singularity," she said. "And this time, the Counter Force would intervene to erase it."
Artoria stood speechless, overwhelmed by the weight of what she had just heard.
But Morgan didn't stop. As though determined to crush whatever hope remained in her, she continued, "Don't panic just yet. Becoming a Singularity is only one possible outcome. There are worse scenarios than that."
Ultimately, even Morgan couldn't be certain how far the corrupted Fuyuki Grail's power could reach.
And in truth, Morgan's own summoning had been even more anomalous than Artoria's.
"You've been going on about the Grail being corrupted since earlier," Kiritsugu Emiya finally spoke, breaking his long silence. "But you're just a Servant with some distant blood connection to that King of Knights over there. Why shouldn't I suspect you're just trying to demoralize the other camps by saying all this?"
Kiritsugu was even more doubtful of Morgan's words than Artoria.
He had entrusted his wish to the Grail, spent nine years preparing and waiting—there was no way he could easily accept that it had all been in vain.
"All the World's Evil," Morgan said, calmly. "Or more precisely—Angra Mainyu."
This time, the first to show a visible reaction was Risei Kotomine.
As the Overseer of the previous Holy Grail War, he was naturally familiar with the classes and even the true names of the Servants that had been summoned back then.
"Judging from your reaction, Overseer of the Holy Church, I'd say you already know what I'm referring to," Morgan said, without even turning her head—yet she was fully aware of the old priest's response. "That is the cause of the Greater Grail's corruption."
Tokiomi's face changed. He had never looked deeply into the previous Holy Grail War, focusing instead on how to win the current one as safely as possible—gathering Holy Relics and other preparations.
After all, no one willingly summons a Servant that's already appeared before. If someone with inside knowledge realized it, that Servant's true name could be exposed instantly.
"Father Risei, what exactly is going on?" Tokiomi asked, keeping his urgency restrained behind polite tones.
As well-read as he was, he knew full well that Angra Mainyu was a deity from Zoroastrianism.
The old priest's expression was stern, his brow deeply furrowed. "That was a Servant summoned in the previous Holy Grail War—an irregular Servant who manifested under the extra class, Avenger."
At that, he narrowed his eyes and glanced toward Kiritsugu Emiya, driven by his moral convictions as a priest.
"Avenger?" Shiomi hadn't intended to speak, but the words escaped him. "You mean that irregular class?"
"That much is unclear. After all, it was the Einzberns—one of the Three Families—who summoned Avenger," Father Risei answered honestly.
Kiritsugu stood, visibly displeased. "Sounds like there's no point in listening any further."
"Don't be so hasty, Magus of the Einzbern," Father Risei said calmly. "I'm not bringing this up to turn the other Masters against you. I'm simply stating the facts. Sixty years ago, the Einzbern did summon Avenger, but that Servant was defeated on the fourth day. The Lesser Grail was then destroyed, and the war ended without a result."
Morgan, satisfied that the priest had explained enough, picked up the thread again:
"Normally, when a Servant is defeated in the Holy Grail War, their soul is absorbed into the Greater Grail and converted into colorless mana. But Angra Mainyu was different. As the embodiment of all the evils of this world, the moment his soul was absorbed, the malice and twisted desires he carried corrupted the Grail itself."
As she finished, Morgan raised a hand, and a mirror formed from water floated into view within the chapel.
"This—this is the current state of the Greater Grail. If this still isn't enough to convince you, feel free to confirm it with your own eyes."
Through Morgan's Magecraft, everyone present could see the image of the Greater Grail. Even though it was only a projection, the abnormality was obvious.
"Utter nonsense."
Kiritsugu left those words behind and turned to leave, disappearing alone through the chapel doors. Artoria, though still full of questions, had no choice but to follow her Master.
While the rest of the factions stopped doubting after Morgan relinquished the right to monopolize confirmation of the truth, Kiritsugu Emiya alone continued to believe that Morgan was lying.
Or rather—something fundamental within him had been shaken, and so... he ran.