Ciel is a quiet and serious person; she also has a relaxed, calm, and rather detached demeanor as a result of her militaristic lifestyle since she was little. 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.
Project X Zone series
Ciel is gonna appear in the Upcoming crossover, Project X Zone 2. She is partnered up with Nana Kouzuki.