Shirou is pulled into creation by a botched ritual, how will he impact the world (if at all) Fate/Stay night x Exalted I must say to read my final notes in each chapter, I normally make note of things like the imaginary number problem. I don't own either exalted or any part of the fate series

It had been 5 years since the 5th Holy Grail War ended, and things were going fairly well for the trio of Shirou, Rin and Saber. Living in London and studying at the Clock Tower, the three had made a nice life for themselves. But when an Apostle hunt goes wrong and Shirou finds himself on the brink of death, he is Chosen by Sol Invictus.

In a fight to dismantle the Grail, Shirou hesitates and loses everything. Banished to a new world, he is given an infernal offer by forces beyond imagination who also failed and lost everything. [Exalted and Fate/Stay Night]