Initially introduced as a villain, Kaine is a complex character whose backstory of trauma and rejection unfolds alongside his evolving relationship with Helena, contributing significantly to the novel's thematic development.

As the antagonist, Morrough instigates fear and tension throughout the narrative with his pursuit of immortality and manipulation of souls, creating conflict for both Helena and Kaine.

A close friend of Helena's, Lila is characterized by her bold and determined nature, forming a crucial part of Helena's support network during their time at the Institute and in the Resistance.

A symbol of the Resistance and close friend to Helena, Luc plays a vital role in welcoming her into the community and is pivotal in the broader political struggle against Morrough and the Undying.

Initially a respected face of the Resistance, Jan's manipulation and political maneuvering create tension and complexity in his relationship with Helena as the narrative progresses.

Kaine’s wife, Aurelia adds tension to the narrative through her feelings of isolation and manipulation, which lead to confrontations that challenge Helena and Kaine's developing relationship.

Luc’s aunt, Ilva’s character is marked by her interest in and manipulation of Helena due to her powers, representing ulterior motives within the Resistance and ties to the Stone of the Heavens.

Kaine's late mother, whose past death is central to his motivations and personal development throughout the story, influencing his relationship with Helena and his quest for redemption.