Takako Honda (Japanese), Lydia Mackay (English)
Cardinal Caterina Sforza, the Duchess of Milan, is a strong willed, determined woman who shows no fear and has a strong resolve in anything she believes in. She is the head of the Ministry of Holy Affairs and leads the department's special operations group, the AX Agency.
Caterina first met Abel Nightroad when he saved her from a group of vampires who attempted to kill her by order of the Contra Mundi. After she was safe, he promised that he would always protect humans. They have been close friends ever since. Caterina greatly loves her brother Alessandro, the current Pope, and has shown herself to be willing to die to protect him. Caterina frequently clashes with her other brother, Cardinal Francesco, who abhors the idea of peace with vampires and has little regard for the life of Alessandro.
Despite her past experiences, Caterina strongly believes in the need for peace between humans and vampires. Though discovery of her actions could result in her execution, Caterina secretly works to form diplomatic relations with the Empire, knowing they both have a much more deadly enemy in the Rosenkreuz Orden. She has used the AX Agency towards this goal, including arranging a joint operation that teamed Abel Nightroad with Empire representative Astharoshe Asran to capture a vampire mass murderer at large in Venice.