Return with Future Knowledge.

Hey write a FATE/STAY NIGHT fanfiction were Emiya Shirou has returned bact to the time when he was saved by Emiya Kiritsugu and the actually starts with little shirou waking up inside the hospital but he's very confused about what's happening because he has all of the future knowledge about fifth holy grail was and studying at the clock tower as a mage, but there is a twist while thinking all of this he hears a *ding* sound and when he try to find the source of this sound a digital game screen appears in front of him and it has the words written on it: [GAMER, DO YOU WISH TO START THE GAME: (Y/N)]
Emiya Shirou woke up to a world he thought he had left behind. He was back in the hospital bed where Emiya Kiritsugu had saved him all those years ago. But something was different this time. He could feel it in his bones. He sat up slowly, looking around the room. It was the same as he remembered it, but he wasn't the same. He had all the knowledge of the future, including the fifth Holy Grail War and his time at the Clock Tower as a mage.
As he tried to piece together what was happening, he heard a strange sound. It was a ding, and it was coming from somewhere in the room. He looked around, trying to find the source of the noise. Then, out of nowhere, a digital game screen appeared in front of him. It had the words written on it:
[GAMER, DO YOU WISH TO START THE GAME: (Y/N)]
Shirou was confused. He had never seen anything like it before. But he couldn't help feeling a sense of excitement. It was like the world was offering him a second chance. He hesitated for a moment before pressing the "Y" button.
As soon as he did, the world around him changed. He found himself standing in a completely different place. It was a vast, open field, and he could see mountains in the distance. The sky was blue and clear, and there was a gentle breeze blowing through the grass.
Shirou looked down at himself and was surprised to see that he was wearing armor. It was a strange feeling, but he knew that he needed to focus if he was going to figure out what was going on.
He looked around, trying to get his bearings. That's when he saw a figure approaching him. It was a woman, dressed in armor similar to his. She had a sword at her side and a determined look on her face.
"Welcome, Gamer," she said, bowing slightly. "I am Saber, your servant."
Shirou was taken aback. He had heard of servants before, but he had never imagined that he would have one of his own. He realized that he was now a part of a game, and he had to play by its rules.
"Let's get started," he said, taking a deep breath. "I have a feeling that things are going to get interesting."