Reborn as Emiya Shirou in Naruto with the Gamer System

The Counter Force is a safety device formed by a World to defend itself against extinction and is synonymous with the World as it represents. All of a sudden, and without any explanation, I saw myself appearing in another world. It felt strangely familiar, but that was just the beginning. (Counter Force: you received the mission to stop the end of Naruto's world.) After trying to understand what was going on, I suddenly realized that I was no longer myself. I had become Emiya Shirou on his first mission to prevent the end of the world as an agent of the counterforce. I never imagined that it would happen and that I would have to save a world like Naruto's at that. Also, I have the gamer's system.