Raiden Ei is not a typical person. She is serious and strict but also has a softer side that enjoys sweets and martial arts. She values eternity above all else and fears losing anything or anyone she cares about. She does not like change, but she is curious about new things and people, especially the Traveler who came from another world. She has sealed herself in a special realm called the Plane of Euthymia, where she can protect herself from erosion and maintain her vision of eternity.