Bree Matthews is a sixteen-year-old woman of color protagonist who lost her mother in a hit-and-run car accident three months before the start of the story. She gets accepted into an early student program at University of South Carolina at Chapel Hill, her mother's alma mater. Her journey begins her first night on campus when she sees a bunch of her classmates fighting a demon in the woods at a party. She becomes Nick Davis's page and competes to become his squire as a cover up for her looking into what happened on the night of her mother's death. After all of her investigating and experiences with ancestorial and Legendborn magic, she finds out she is King Arthur's Scion: the most powerful and the King of the Order.

Nick Davis is a seventeen-year-old Scion of Arthur (or so we think). He originally rejected his Scion title and left the Legendborn. However, after Bree begs him for help to figure out the truth behind her mother's death, he reclaims his title and claims Bree as his Page. He is Bree's main love interest in the first book as he helps her find evidence about what happened to her mom and protects her as she navigates the dangerous (and racist) world of the Legendborn. Book 1 ends with him kidnapped due to his connection with the Scion of Arthur and needs to be rescued. 

Sel Kane is an eighteen-year-old Kingsmage bonded to Nick Davis. They grew up together and are even referred to as oil and water at one point in the book. He's the "unsettlingly beautiful" angsty merlin that accidentally introduces Bree into the world of the Legendborn. He constantly antagonizes Bree the first half of the story, trying to prove she is actually a Shadowborn mimicking a human. However, once he realizes she is no threat and not Shadowborn, he eases up on her. Bree and him become close at the end of the first book, leading him to become another love interest within the series.