Nerissa is self-absorbed and thinks the world revolves around her. She is a "Little Miss Perfect" type character with very high standards at Oceanside High School, given the fact that the students love everything about her. She is a deception-master, as evidenced that none of the humans suspect who Nerissa really is, and she lacks remorse for manipulating people, and her true focus is getting power for herself. She appears to be somewhat sadistic and hates the Gillman family with a passion.