Ciel was acquainted with Julius during her time at the Magnolia Compass, though she did not bond with him to the level of friends. She spent a childhood following strict orders and was taught that rules were more important over matters. Due to this strict upbringing, she was unable to develop her social ability and found it hard to respond in normal conversations. Years later she joined Blood and asked the Protagonist to be her first friend. When she was trapped in the red rain in a mission to protect a malfunctioned God Arc Soldier from Aragami harm and adhered to the Friar Director's orders to protect the God Arc Soldiers and stay instead of following Julius's inferior authority to save herself. The protagonist disobeyed the Friar Director's orders and rode in a God Arc Soldier to rescue Ciel from the red rain and a Chi-You. After being put into temporary confinement quarters, Ciel conversed with the Protagonist over the Protagonist's reasoning in disobeying orders and the risks taken and learned from the Protagonist of the warmth of protecting one's precious people. She also assisted in the rescue of the kidnapped Black Plague infected children aboard the Friar. Ciel is part of the remaining Blood team at the confrontation against the Person Who Opens the World.
Ciel is a quiet and serious person; she also has a calm and rather detached demeanor as a result of her militaristic childhood. This also left her wanting on a social level, though this does have its finer points, as it lets her keep her fellow Blood members in line. Her interactions with the protagonist allow her to develop as a person, subsequently letting her make friends with the rest of Blood.
Ciel is a teenage girl with a pale-white skin, silver hair and silver eyes. She wears a gothic lolita dress with corset, a black boots and 2 black hair pins on her hair in twintails.
- Protagonist (God Eater 2) - Her first friend and leader. Created the Blood Bullets through their help, as well as the module that would allow them to put together their own special bullets.
- Julius Visconti - The person she was assigned to protect as a bodyguard in her childhood. While they got along, they were merely acquaintances at best.
- Ciel is French for "sky".
- Ciel has a combat knife strapped to her thigh under her skirt and a pistol on her chest holster, which are never shown to be used.
- Ciel's Power of Blood gives "Enemy HP Vision" and "Sensitive" to all party members on the field.
- Her Blood Art is the evasive aerial square attack, Flying Lotus renamed Silent Lotus on her Personal Ability page.
- Ciel first discovers the existence of Blood Bullets and helps the Protagonist expand on BB editable potential.
- After fulfilling episode events with Ciel, she will be able to use Blood Bullets.
- Due to Ciel's care, the Anagura Lounge's Capybara has grown massively.
- Both Ciel and Kate are voiced by Mamiko Noto.