Illumise resembles a firefly with feminine traits. Her body is black and blue, with two vertical stripes going down the front. Her arms and legs are black as well, and are connected to the body by purple borders. On her front is what resembles a yellow bow or shawl. She has large, slanted eyes with blue irises, and appears to be smiling, unlike her male counterpart, Volbeat. Surrounding her head is a purple appendage with curls at the end that frame her face. Her antennae are also smaller than Volbeat's, and are yellow in color. Illumise has small wings used for flying with others of the species. Illumise has a pattern of three oblong yellow spots on her rear.