Alex's pure-blood mother, known for her willowy frame and striking green eyes. Her decisions significantly impact Alex's life, and her past actions align with quiet rebellion against societal norms.

A 20-year-old pure-blood Sentinel with dark hair and gray eyes. He serves as Alex's mentor and harbors a past marked by tragedy, profoundly influencing his reserved nature and protective instincts.

Alex's best friend and fellow half-blood, known for his humor and unwavering support. He acts as a stabilizing influence in Alex's life while navigating the constraints of their world.

The strict and often unsympathetic Dean of the Covenant, who initially opposes Alex’s training. His character is more complex than he first appears, with motivations that evolve over time.

Alex's influential stepfather and a Minister on the Hematoi Council, whose outward facade of concern conceals deeper, self-serving motives. His intentions towards Alex and her abilities remain ambiguous.

The first Apollyon, set apart by his unique powers and striking appearance, with moving tattoos only visible to Alex. He is connected to Alex but grapples with his constrained position and blunt demeanor.