Fate/Prototype

Ayaka Sajyou, the sole survivor of a magus family, tries to live quietly and away from her past until Sancraid Phahn warns her that the Second Tokyo Holy Grail War is about to begin. Hunted that same night by a spear-wielding Servant and his familiars, she is rescued by a knight she summons as Saber, whose true name is Arthur Pendragon. This short OVA bundled with Carnival Phantasm dramatizes Kinoko Nasu's early prototype of the concept that later became Fate/stay night.