An Archer's Promise

In Archer's last moment during the Grail War, he made a promise to Rin, to try his best. Not knowing if he was even capable of keeping up such a promise, while in the service of the Counter Force. Bow sent to a new world to deal with its rising threat, how will our favourite cynical hero deal with the people of this strange yet dark world? a Fate X Kuroinu crossover fic.