Fate/Prototype: Manaka Sajyou

She is Ayaka's older sister, the previous Master of Saber, and the one responsible for the tragedy that occurred in the second Holy Grail War. She also acts as the Master of Beast, which is the Beast of 666, an monster that was written of in the Book of Revelation from the Bible that said to be the one who wore ten crowns symbolizing the sins and greed of humanity. Her position as Master is under The First, Seraphim. She is truly twisted that is hidden by her innocent behavior towards Saber, to a disturbing level, trying to act innocent to him. But, deep down, she is monstrous, capable of killing her father and tearing him to pieces, and capable of being used as a sacrificial ingredient for the Grail simply because she is ordinary, all while smiling like an angel without any sign scorn or ill will. In terms of abilities, she is a very powerful magus, who is proficient in all magecraft, with talent that surpasses even the magi from the Age of the Gods, even Caster stated that she is more powerful than her own Servant, and Saber himself says that she far surpasses regular Servants.