Alina is a plain, sickly orphan who works as a mapmaker for the King's Army. She covers her loneliness with a spunky personality but harbors a deep, secret affection for her childhood friend, Mal. When her unit is attacked on the Shadow Fold, she unknowingly releases a powerful burst of light, revealing she is a rare Grisha known as a Sun Summoner.

Mal is a charismatic and highly skilled tracker in the First Army who grew up alongside Alina at the Duke's orphanage. Popular and outgoing, he fits in easily among the soldiers, standing in contrast to Alina's isolation. He is deeply bonded to Alina, though he initially appears oblivious to her romantic feelings for him.

The Darkling is the ancient, immensely powerful commander of the Grisha Second Army. Despite being over a hundred years old, he appears close to Alina's age. He is a living amplifier and a Shadow Summoner capable of controlling darkness, and he takes immediate charge of Alina upon discovering her light-summoning abilities.

Baghra is an ancient, eerily skull-faced Grisha instructor who resides in a hut near the Little Palace. She is tasked with teaching Alina how to access and control her powers. Notoriously cruel and intimidating, she relentlessly pushes her students to their limits.

Genya is a beautiful Grisha Tailor assigned to serve the Queen at the Grand Palace. Because her power focuses on altering physical appearances, she is looked down upon by other Grisha and forced to wear a white servant's kefta. She quickly befriends the newly arrived Alina, helping her adjust to the social hierarchy of Os Alta.

Zoya is a talented and highly ranked Grisha Squaller who wears a silver-embroidered blue kefta. She is confident in her elevated status and holds a favored position among the Grisha. She immediately takes a strong dislike to Alina, viewing the newcomer as a threat to her own standing.

Ivan is a high-ranking Corporalki Heartrender who wears a red kefta. He is cold and exceptionally loyal to the Darkling. He possesses a magical amplifier that increases his abilities to manipulate the human body, making him a formidable soldier.

David is a serious, highly intelligent Grisha Fabrikator who specializes in creating materials, weapons, and inventions for the Second Army. He spends his time focused on his work in the workshops, completely oblivious to the romantic attention he receives from others.

Marie is a friendly Grisha Etherealki who wears a blue kefta. She attempts to welcome Alina into the fold of the Summoners at the Little Palace. She is highly attuned to the gossip and social dynamics of the Grisha hierarchy.

Nadia is a Grisha Etherealki who forms a close friendship with Marie. Like her friend, she tries to bring Alina into their social circle and eagerly shares rumors about the other Grisha and the royal court.

The Apparat is a peculiar and unsettling priest-like figure who operates within the royal court. Smelling of mildew and incense, he holds significant but ambiguous influence over the King. He takes an intense, eerie interest in Alina, suggesting her arrival aligns with the religious beliefs of the common people.

The ruler of Ravka, who presides over the decadent Grand Palace. He is an incompetent and self-indulgent monarch who prioritizes luxury over the suffering of his war-torn country. He relies heavily on the Grisha to maintain his military strength.

The vain and dramatic royal consort of Ravka. She lives a life of extreme privilege in the Grand Palace, entirely disconnected from the poverty of the regular citizens. She employs Genya to magically maintain her flawless appearance.

Botkin is a former Shu Han mercenary who serves as the combat instructor for the Grisha at the Little Palace. Because he is not Grisha himself, he strictly forbids the use of magic during his physically demanding sparring sessions, forcing his students to rely entirely on their bodies.

Alexei is a junior cartographer in the First Army and a friend of Alina's. He represents the ordinary soldiers who risk their lives crossing the treacherous darkness of the Unsea without the aid of Grisha magic.

Sergei is a Corporalki Grisha who holds a high rank within the Second Army. He is highly protective of the strict hierarchy that governs the Grisha and feels his superior status entitles him to certain privileges.

Ana Kuya is the housekeeper at the Duke's orphanage where Alina and Mal grew up. She was a strict, overbearing figure who managed the refugee children and enforced the rules of the estate.