Aerin is the protagonist and hero of the novel. Over the course of the nonlinear narrative, she grows from an inexperienced child to a young adult. Aerin is characterized as courageous, determined, and awkward. While she is multitalented in many physical areas, she is repeatedly shown to lack the refined social skills that her country expects a sol to possess. The narrative soon establishes Aerin as an unusual young woman who stands out among her peers; the contrast built between her and her cousin, Galanna, further delineates this.

Aerin is specifically described as having “fiery” red hair, pale skin, and green eyes, all of which are perceived as unusual and “witchlike” physical traits. Her hair also aligns with her behavior—like the stereotype for redheads, she is quick to anger and regularly acts on that anger, such as when she eats the poisonous surka plant on a dare or cuts off Galanna’s eyelashes. As the daughter of the king and his late wife, Aerin is the “first sol,” or the highest-ranking princess of Damar, a position that contrasts with her more traditionally “masculine” interests and behavior, like horseback riding and dragon-hunting.