Illya exhibits a demeaning and negative attitude; but unlike her counterpart, she is not shy, easily flustered, and less innocent at the beginning.

She is an ardent fan of manga, much to Sella's disappointment. She secretly harbors feelings for her brother, Shirou, something that Ruby highlights frequently much to her embarrassment. She is very clingy when with him and desires him only for herself.

Illya Alter is an Evil version of her magical girl self and will do anything to achieve her goal