Diem is a 20-year-old healer living in a remote village outside Mortal City in Lumnos. Born with brown hair and eyes that mysteriously turned white and gray, she takes a daily dose of flameroot powder to suppress her fiery temper and alleged hallucinations. She is fiercely protective of her family and highly empathetic toward her medical patients. When her mother suddenly goes missing, Diem sets out to uncover the truth behind her family's hidden history.

Prince Luther is the nephew of King Ulther and a prominent figure among the Descended, an elite class of rulers with divine blood. He possesses a steely, formidable exterior and powerful magic, making him a feared presence among mortals. Though initially presenting as arrogant and demanding, he shows fierce protectiveness over those he cares for, especially his younger sister.

Henri is Diem’s childhood best friend and occasional romantic partner. He is earnest, sensitive, and deeply committed to the mortals' struggle against the Descended rulers. His intense hatred for the elite class draws him into the Guardians of the Everflame, a rebel group planning to seize control of the Descended territories.

Andrei is Diem’s adoptive father and a legendary former soldier who fought his way to the highest ranks of the Emarion Army. He chose to leave his military career to raise his children in a quiet, secluded village. He is highly protective of his family and trains Diem in martial defense, though his lingering loyalties to the Descended army create friction within his household.

Auralie is a mortal healer and the matriarch of the Bellator family. She acts as a fiercely protective mother, isolating Diem from the Descended world and administering flameroot powder to suppress her daughter's unusual traits. Her secret arrangements with the royal family and sudden disappearance serve as the catalyst for the events in Emarion.

Teller is Diem’s 17-year-old younger brother. Despite being a mortal, he possesses exceptional intelligence and attends the prestigious Descended school due to a secret arrangement made by his mother. He exists in a difficult social limbo, torn between his mortal peers and his elite classmates.

Maura manages the local healing center where Diem works. She is a practical, dedicated medical professional who encourages Diem to take time for herself but strictly enforces the rules when treating Descended patients. She worries constantly about the dangers of mixing mortal healers with royal affairs.

King Ulther is the ailing monarch of Lumnos and a powerful Descended ruler. His mysterious illness requires specialized care from mortal healers, including Auralie and later Diem. His declining health creates a volatile political climate as factions prepare for his eventual passing.

Princess Lilian, often called Lily, is King Ulther's niece and Prince Luther's younger sister. She attends the Descended school alongside Teller. Despite her elite royal status, she is open-minded and grateful to the mortals who assist her, showing none of the typical prejudice expected from her class.

Brecke is a resident of Fortos and a committed member of the Guardians of the Everflame. He is deeply entrenched in the rebel movement and supplies Henri with illegal goods and weapons. He holds crucial knowledge about Auralie's past movements and provides Diem with a rare Fortosian steel blade.

Elric is a Descended man whose reckless use of magic causes a structural collapse at the palace, injuring several children including Princess Lilian. Panicked and remorseful, he abandons social protocols to seek out mortal healers to fix his mistake.

Evanie is a young Descended girl whose father holds valuable intelligence. She is secretly poisoned with nightshade by the Guardians of the Everflame to create a distraction, allowing Diem to infiltrate her home under the guise of healing her.

Lorris is a young Descended boy who acts as a worried brother when his sister Evanie mysteriously falls ill. He unknowingly facilitates a rebel intelligence mission by bringing Diem into his family's home to administer care.

Leona is a warehouse worker in Fortos who guards highly regulated substances. She acts as a gatekeeper to the flameroot powder Diem desperately seeks, strictly enforcing the rule that only the king can authorize its distribution.