"My designed lifespan was originally only nine years, but thanks to your efforts, it was forcibly extended to twice that..."
"Now, there's no way to extend it any further."
Volume Four, 166: Illya's Birth (?
As an Artificial Lifeform (Homunculus), Irisviel von Einzbern had a designed lifespan of only nine years.
According to the original plan, she should have died the moment Einzbern achieved victory. There was no way she could have lived past the Fourth Holy Grail War.
However, during that ritual, Irisviel herself developed the desire to "keep living," and ultimately betrayed her family.
After the war, Irisviel's life was extended, far beyond the limit she was originally meant to have.
Shirou had also believed she would live as long as an ordinary human—no, deep down, he had hoped for that.
Although Irisviel had unilaterally declared herself Shirou's "mother" at first, after fighting and living together for so many years, Shirou had long since come to regard her as his true mother.
Irisviel's life ending here... No, he couldn't accept that!
Shirou wanted Irisviel to remain by his side forever. Even if a long life was impossible because of her fate as an Artificial Lifeform... at least let her live another ten years. No, thirty years!
Shirou forced a smile.
"Hahaha... Irisviel, what are you talking about? You really know how to scare people.
"You haven't reached the end of your lifespan. You're just sick. As long as you rest for a few days and obediently accept treatment, you'll recover."
Irisviel shook her head and said, "Shirou, you don't need to comfort me like this. I know my own body better than anyone."
"..."
Shirou furrowed his brows as an inexplicable flame of anxiety surged in his chest.
"That's why I told you to stop talking about