Who is Harmony from The Game and what is their importance?

Harmony is Hayley's cousin and Troy's sister. She is in college, and initially Hayley mistook her for one of the aunts. Harmony is in charge of the game, and she is the most skilled of the cousins at traversing the mythosphere. In Greek mythology, Harmonia (Harmony) is the daughter of Jupiter (Uncle Jolyon) and Electra.