Jack the Ripper, also known as the Legendary Serial Killer (伝説の連続殺人鬼), is a fictional character from the Fate/Apocrypha series who belongs to the Assassin class. She is depicted as a young girl with dual natures, appearing both innocent and ruthless in her actions. Despite her childish demeanor, she possesses quick thinking skills and rationality dominates her behavior. However, her psyche has inherent weaknesses that make her vulnerable to mistreatment. Her personality is complex, capable of being both pure and cruel, and she tends to respond to kindness with kindness and cruelty with cruelty. Due to her need for human souls to survive, she only consumes the souls of evil individuals, finding their "taste" more satisfying than that of innocent people.