The Ryudou family has welcomed an esteemed guest to their temple, where she resides until the completion of her marriage preparations. This enigmatic woman is both beautiful and skilled, drawing the attention of many trainee monks. Caster is a rogue who holds a deep-seated grudge against Tohsaka due to her draining of mana from the townsfolk and almost killing them in the process. She is relentless, cunning, and driven by ambition. Assassin serves as her gatekeeper at her base of operations, while Caster displays an interest in all protagonists, including Saber, whom she hopes to claim for herself. Although physically weak, Caster possesses formidable anti-Army magic, Territory Creation abilities, and skeletal golems that make her a force to be reckoned with in battle. However, she may struggle in one-on-one combat situations.
She was Medea in her past life.