The Fifth Holy Grail War in Fuyuki City has reached a turning point in which the lives of all participants are threatened as the hidden enemy finally reveals itself. As Shirou Emiya, Rin Toosaka, and Illyasviel von Einzbern discover the true, corruptive nature of the shadow that has been rampaging throughout the city, they realize just how dire the situation is. In order to protect their beloved ones, the group must hold their own against the seemingly insurmountable enemy force—even if some of those foes were once their allies, or perhaps, something more intimate. As the final act of this chaotic war commences, the ideals Shirou believes will soon be challenged by an excruciating dilemma: is it really possible to save a world where everything seems to have gone wrong? [Written by MAL Rewrite]

After a mysterious inferno kills his family, Shirou is saved and adopted by Kiritsugu Emiya, who teaches him the ways of magic and justice. One night, years after Kiritsugu's death, Shirou is cleaning at school, when he finds himself caught in the middle of a deadly encounter between two superhumans known as Servants. During his attempt to escape, the boy is caught by one of the Servants and receives a life-threatening injury. Miraculously, he survives, but the same Servant returns to finish what he started. In desperation, Shirou summons a Servant of his own, a knight named Saber. The two must now participate in the Fifth Holy Grail War, a battle royale of seven Servants and the mages who summoned them, with the grand prize being none other than the omnipotent Holy Grail itself. Fate/stay night follows Shirou as he struggles to find the fine line between a hero and a killer, his ideals clashing with the harsh reality around him. Will the boy become a hero like his foster father, or die trying? [Written by MAL Rewrite]

As the Fifth Holy Grail War reaches its conclusion, Saber repeats her final duty from the previous war in order to end the vicious cycle once and for all. With the decisive blow draining her remaining mana reserves, Saber's body begins to dissipate. She utters a tearful farewell—but Rin Toosaka reaches out to her at the last moment. The future has been changed, and a new beginning awaits. [Written by MAL Rewrite]

In the midst of the Fifth Holy Grail War, Caster sets her plans into motion, beginning with the capture of Shirou's Servant Saber. With the witch growing ever more powerful, Rin and Archer determine she is a threat that must be dealt with at once. But as the balance of power in the war begins to shift, the Master and Servant find themselves walking separate ways. Meanwhile, despite losing his Servant and stumbling from injuries, Shirou ignores Rin's warning to abandon the battle royale, forcing his way into the fight against Caster. Determined to show his resolve in his will to fight, Shirou's potential to become a protector of the people is put to the test. Amidst the bloodshed and chaos, the motivations of each Master and Servant are slowly revealed as they sacrifice everything in order to arise as the victor and claim the Holy Grail. [Written by MAL Rewrite]