Kyou kara Akujo ni narimasu! Tsukaisute no Migawari Seijo Nante Gomen desu

Princess Leonora is the one and only saint of healing. Ada, the maid of honor, who has been secretly healing people with her miraculous powers, has become a wreck due to the excessive use of her powers. Furthermore, Leonora, whom she had looked up to like a sister, has been cut down and thrown into the water! She thought she was already dead, she is rescued by a group of mercenaries from a big country and invited to become a real saint and show them how it's done!