Fate/Stay Night: Unlimited Blade Works

Ten years ago, in the aftermath of the Fourth Holy Grail War, Illyasviel had a vision of her mother Irisviel, who claimed her husband and Illyasviel's father, a participant in the war, betrayed them by refusing to accept the Holy Grail when it presented itself to him. At first, she refused to believe it, but realized the truth when her father did not return home. As time passed, she stumbled upon a room in her home, containing numerous homunculi that were created to serve Illyasviel's purpose, only to fail in their missions. Realizing she too is a homunculus from their dying messages, Illyasviel became disillusioned with her life. Later on, she met her current maids, who assisted her in summoning Berserker. However, she initially did not want it, resolving to participate and win the Holy Grail War by herself. During the final test of her Master-Servant link ritual, she became lost in the nearby woods, being separated from Berserker, and was mauled by a pack of wolves. Berserker rescued her, and afterwards, she realized it was protecting her out of its own free will. In the present day, Illyasviel and Berserker continue their battle against Shinji's Servant as Shirō and Rin arrive to witness the event. As the battle reaches the main entrance, the Servant eventually restrains Berserker using chains fired from his Noble Phantasm, allowing him to impale Berserker with a large spear. Then, he blinds and then stabs Illyasviel with a sword; as she crawls to Berserker's side, it makes one last attempt to strike the Servant, only to be killed. Shirō attempts to intervene, but Illyasviel dies in comfort, believing Berserker is still at her side.