|Place of origin||Billiana Forest|
|Japanese voice actor(s)||Mao Motomura (Evergrace)|
Height: Approximately 5.6 ft.
Sienna is very resourceful and intelligent. She also has a great deal of motherliness. She bears a Crest and the judgments from others have caused her to become slightly negative and bitter.
Sienna is the daughter of the leader of Toledo clan, which was destroyed by Morpheus. She is kindhearted and loved by her people, and was to be the clan's next leader. Breaking clan rules, she saved a human from the Rieubane Empire. However, her kindness was her sin, and she was taken to the Human Research Laboratory. She escaped but was pursued by Chief Scientist Morpheus as an experimental subject for the Quasi Crest "AI Crest." She seems to have something to do with the destruction of the Rieubane Empire.