Fate/Zero: Onegai! Einzbern Soudanshitsu

The Fourth Holy Grail War in Fuyuki City is described in Fate/Zero, which takes place ten years before the events of Fate/stay night. The Einzbern, Matou, and Tohsaka families created the Holy Grail War, a competition in which seven mages summon seven Heroic Spirits to compete and earn the power of the "Holy Grail," which grants a wish to each member of the victorious pair. The Fourth War begins after three unsuccessful fights for the elusive Holy Grail. After three failures in a row, the Einzbern family is committed to winning the Fourth War at all costs. As a result, despite his techniques and reputation as a proficient hitman who uses whatever means necessary to achieve his objectives, they have decided to add the infamous "mage killer," Kiritsugu Emiya, to their ranks. Even though Kiritsugu previously aspired to be a hero who could save everyone, he has long since given up this goal after discovering that oftentimes, saving one person means risking the life of another. Due to his limited resources and powers, this is the conflict that he once sought to resolve. He decides to ruthlessly annihilate everything and everyone who poses a threat to other people's safety for the good of humanity.