The Man, The Machine. - a Fate fanfiction

One man vowed to carry all evils of the world, if it would mean bringing it's salvation but.. at what cost?
In the end, the only change kiritsugu Emiya was able to bring was complete destruction, and all his sacrifices turned out to be completely worthless, leaving an empty shell of a person in the process.
Many years later, after his untimely death, the little boy he saved, Shirou Emiya, reached out to his adoptive father, summoning him as an assassin - class servant for the next holy grail war, and all the dark secrets Kiritsugu tried to hide, threaten to reach the surface and destroy the only bond this broken man had left.

The characters and story belong to the anime Fate and they have all the credit for the world this story takes place in.

In this story I reimagined what would happen if Shirou Emiya were to get his adoptive father, Kiritsugu as an assassin class servant, so the events in this story are pretty unrelated to the cannon of fate/stay night/unlimited blade works, but affected from the events of fate/zero, it's a mostly character centered story, and it could contain harsh subjects like violence, gore, and suicide, so this is a warning to all of you because I don't want my story to affect anyone negatively.

I hope you'll enjoy, and I know my writing isn't the best, but I'll try to improve.