He could see the grail before him, it was just within arms reach. Kiritsugu had sought after it for as long as he could remember and now he was finally here. He took several steps forward, then abruptly stopped as if he had been frozen in place. His mind couldn't help but wander to the memories of all those he had to sacrifice to get to this point. He had loved Irisviel, and even if he knew from the start that he was always going to be the cause of her death, he couldn't help but feel an overwhelming regret. In truth he would have easily abandoned everything just to be with her, but he knew that the grail was far more important than his own desires. The fate of mankind was more important than anyone, even Irisviel.
He willed himself to take several steps forward until he was within reach. It was beautiful. It was a beauty which he could not easily describe, but at that moment the grail seemed to be the center of his entire universe. Yet, he couldn't shake a feeling of foreboding. He leaned forward and ran his fingers over the cup.
Images seemed to vividly flicker through his mind. Images of sitting by Irisviel on a cold winters day, waiting for Illya to open her presents. Images of Illya going to school and spending the evening telling him about her day. They were fake memories, yet they seemed so real he could almost reach out and touch them.
The images eventually stopped and he found himself standing before the grail again. The grail was a beautiful thing he thought. It was surely the answer to everything. No more war, no more fighting. This was the only way to save the human race. And maybe, just maybe, he might be given a glimpse of happiness. If only he could see Irisviel one more time...
He reached out and grabbed the grail, lifting it into the air as his lips formed into a content smile. By now it was too late, and Kiritsugu barely had time to notice. A black liquid oozed from the cup and devoured him whole. Not satisified with only taking Kiritsugu, the liquid began to spread out to the corners of the room. Saber lifted her sword, though it was no use. The liquid had already covered her ankles and she had been frozen in place. No amount of struggling could stop the liquid from dragging her down into the dark abyss below her.
Kirei stood on the outskirts, watching as the grail continued to devour the entire population of Fuyuki city. It would no doubt spread across the world, spreading death and despair like wild fire. A thin smile formed on his lips.
"Thank you Kiritsugu. I truly thank you."
For once, Kirei had finally felt fulfilled. Watching the grail slowly devour the world was beautiful, and yet, he had thought that he would never live to experience true beauty. How wrong he had been!
This is the beginning, he thought as the smile broke into a fanatical laugh. The liquid crept closer and closer to his feet, yet he paid it no heed. He felt nothing but content.