Aozaki Aoko Case File

Due to concerns that the Rheingold might interfere with the ritual for soul duplication, Acht decided to temporarily halt the process. He ordered the homunculi to remove all items in Winter Castle related to the Rheingold, including the artifact itself, and have them sent out of the territory.

Aoko and Touko voiced no objections to this decision. After all, failure would bring them no benefit, and waiting a little longer didn't bother them.

Even with the loss of the Rheingold, Einzbern's thousand-year accumulation of resources wouldn't be depleted so easily. Moreover, Aoko was confident that once she took over the Einzbern family's assets, she could leverage this start-up capital to profit significantly during pivotal moments, such as the collapse of Japan's economic bubble and the dissolution of the Soviet Union. Elevating the Aozaki family to a new social class in the mundane world would be an effortless endeavor.

Since this detour was deemed necessary, Aoko and Touko went to have lunch. Once the maid tasked with discarding the gold returned to the castle, everyone reconvened in the alchemy laboratory.

The operating table in the lab had been moved aside, replaced by an enormous magic circle drawn by Touko. The text within the circle was written in modernized runes, reconstructed by Touko herself. The intricate script filled every corner of the magic circle, spanning tens of thousands of words.

The general shape of the magic array resembled the mathematical symbol for infinity (∞). Within the left closed structure lay Irisviel, while her duplicate body occupied the right. The two bodies were positioned head-to-head, with their heads closest to each other and their feet farthest apart.

The new body, though identical in appearance, was created entirely with Touko's technology, using Einzbern's techniques only as a reference. Internally, it was entirely different from the original.

Standing at the central point of the ∞-shaped circle, Touko extended her fingers and began inscribing a series of runes in midair while chanting incantations to activate the magic array. As the ritual commenced, the entire array emitted a brilliant white light. Irisviel, lying on the left, suddenly felt a tingling sensation throughout her body, as though something was delving deep inside her, scrubbing her soul inside and out.

The sensation was indescribably strange—not painful, but carrying a sense of profound vulnerability, as though all her secrets were being laid bare. Just as Irisviel reached her limit, the ritual ended.

"You can get up now, Irisviel," Touko's slightly exhausted voice called out. With some effort, Irisviel stood up from the floor. As she turned to look at the other side, she saw her duplicate mirroring her actions, staring back at her.

It was like looking into a mirror.

That was Irisviel's first thought.

"Oh, oh, oh!"

Acht's eyes widened as he immediately approached the duplicate Irisviel. Using various alchemical techniques, he inspected the soul of the duplicate to verify the success of Touko's duplication process. The results were flawless.

Acht, whose understanding of Einzbern homunculi souls was unparalleled—even surpassing the still-living Makiri Zolgen—concluded that there was no discernible difference between the two. Even Jubstacheit von Einzbern, the foremost expert on homunculi, would be unable to detect any flaws or traces of duplication in the duplicate Irisviel's soul.

If not for the fact that one body served as the Lesser Grail while the duplicate lacked that functionality, both could be defined as Irisviel von Einzbern. Even their origin concepts were identical.

Was this the terrifying power of the Grand Puppeteer?

Acht felt the vast gulf between genius and mediocrity more acutely than ever.

"Einzbern has now witnessed the extraordinary capabilities of Lady Aozaki Touko," Acht said respectfully to the smug Touko and the seated Aoko.

"Now, we can begin discussing the specifics of our collaboration."

"...However, I still have one small question," Acht added, pausing.

 "Why didn't you replicate the Lesser Grail's functionality?"

"Because it's meaningless," Touko replied after taking a sip of the potion Aoko handed her.

"Why would you make the Lesser Grail in the form of a human? Is it to make it easier for a homunculus soul to control the Greater Grail? Without the Heaven's Dress as your controller, what's the point?"

"You must understand, Mr. Acht that any task conducted by humans carries a risk of failure," Aoko added meaningfully.

Acht had no rebuttal for the sisters' reasoning. Even as an artificial intelligence, he couldn't deny their logic. The existence of Irisviel von Einzbern as a humanoid Lesser Grail had already lost its purpose.

...

Elsewhere.

Kiritsugu Emiya paced back and forth anxiously, a situation that reminded him of waiting for his daughter's birth with Irisviel. Despite his infamous reputation as the Magus Killer, Kiritsugu was powerless against Acht and the wielder of the Fifth Magic.

No matter what methods he employed, there was no way for him to stop Acht or the young magus from experimenting on his wife. After all, both Irisviel and their daughter were creations and possessions of Einzbern. What right did he have to interfere?

Kiritsugu, the man, was lost. What meaning did "the salvation of humanity" hold if he couldn't even protect his wife and daughter? How could he continue to pursue humanity's salvation?

He didn't understand complex magical theories. His knowledge of the Einzbern Holy Grail ritual and its connection to the Third Magic was only superficial. The only thing Kiritsugu understood was that the omnipotent, wish-granting Holy Grail could save him from his painful, empty life.

Throughout his life, Kiritsugu had witnessed too much suffering and too many evils. These experiences had shaped him into the man he was. To him, there was only one way to free the world from this endless whirlpool of suffering: to make a wish upon the Holy Grail.

But the cost of that wish was his wife.