She has lavender skin, long two-tone purple hair with bangs, red lips, aqua eyelids, and green eyes. Her outfit consists of a dark purple dress with a knee-high slit, red flats, and a red belt.
During exercises, she temporarily wears a red sweatband and pink leg warmers. She is tied with Phantasma as the second tallest girl in school, falling short of Elsa Frankenteen. She can turn into a bat like all other vampires.
Sibella's color scheme is incorporated into her bat form, as when she turns into a bat, she keeps her green eyes and aqua eyelids and has a lavender face, dark purple body, purple wings, and purple legs.
She is very kind and polite. She compliments other people often, showing she has good people skills. She is also very helpful and generous.