Fate: Sword Order by Parcasious .Fate/stay night -

A certain technician is invited as a member of Chaldea's staff until a chance discovery changes everything and lands him into an ordeal with the fate of Humanity itself at risk.Fate/stay night - Rated: T - English - Chapters: 19 - Words: 110,598 - Reviews: 3136 - Favs: 6,179 - Follows: 7,204 - Updated: Apr 14 - Published: Jun 23, 2020 - Shirō E., Mashu/Shielder, Olga Marie, Ritsuka F. that one is a harem bet is good fanfic