Rumia is apparently quite simple-minded and doesn't like the sunlight nor the summer heat; in fact, she uses her powers of darkness to surround herself in a mass of dark, as to avoid the heat and the light. It is also said that she only uses this power as a supportive ability when attacking others, using pure strength as her main asset. She seems to like flying around aimlessly during the day and night, sometimes bumping into trees since she is less capable of seeing obstacles through her veil.