Ellington “Elli” Asher is the deuteragonist of The Sinner, or the novel’s second-most important figure. Like Sin, she is a student at Barrington University. She is portrayed as intelligent and motivated, and is more invested in her studies than the other student characters. Her endeavor to become a sex therapist is a key element of her character development. Unlike Sin, Elli is a dynamic character, growing and changing over the course of the novel. The focal point of her growth is linked to her studies, which help her to become more comfortable with her traumatic past. The novel reveals that Sin is the only person with whom Elli has had consensual sex.

Elli’s exposure to sex through her mother’s sessions instilled a sense of sexual morality in Elli, in which the desire for sex, especially sexual play like bondage or violent sex, became immoral. James’s abuse heightened this sense of “dirtiness,” which eventually led Elli to see herself as a “whore” unworthy of true love. Over the course of the novel, Elli gradually accepts Sin’s love for her in conjunction with their violent sexual experiences, which allows her to start moving past her trauma. Elli resolves her feelings of helplessness and worthlessness by adopting Laura and Liam’s child, allowing her to break the cycle of abuse that tormented her.

Elli is defined by her struggles with sex, drugs, and relationships. In overcoming these challenges, she grows as a character. A key moment in her development is when Chance and Holland, masked, force Elli to take ecstasy and threaten to sexually assault her. Though this scenario is Elli’s fantasy at the beginning of the novel, she feels disturbed. This suggests that she now connects sexual play to the love and care of a relationship, something she can only share with Sin. Her growth culminates in her decision to continue pursuing sex therapy and to keep her career separate from her children’s lives, in contrast to how Laura held sessions in the family home.

Kira Sinnett is Elli’s best friend and Sin’s sister. She is a supporting, secondary character in the text; she primarily acts as a check on both Sin’s immorality and Elli’s mental health. Whenever Sin does something that crosses a moral line, such as trying to convince Elli that he does not love her, Kira chastises him and encourages him to rectify the situation. Likewise, when Elli endures hard moments in the novel, such as after Lincoln assaults her in her bedroom, Kira appears to comfort and support her.

Through Kira, the novel also explores the distinction between Sin’s understanding of women as objects and his love for the women in his own life. Just as Sin does not want anyone touching Elli other than him, he does not want Kira to be involved in the Lords’ business, despite acknowledging how it’s inevitable that those born into the society will ultimately become involved.

Kira also represents an alternative life path for Elli. Elli often notes how the abuse of her youth affects her into the present, whereas Kira’s upbringing protected her from sexual violence.

Corbin is Kira’s boyfriend and Sin’s friend. He is a minor character, but, along with Jayce, Corbin helps Sin accomplish his tasks. Though Corbin’s role in the text fades over the course of the novel, he is instrumental in establishing Sin as a powerful Lord. He is a benevolent character who gradually reveals that he truly loves Kira, supports Sin, and wants to help both of them succeed in their goals. It is possible that Corbin and Jayce will eventually receive their own novels in the L.O.R.D.S. series, which usually draws on a different Lord to serve as the protagonist of the work.

Liam Sinnett is Sin and Kira’s father, and he serves as the primary antagonist of the text. James, who has died before the novel’s events, was the catalyst of Elli’s trauma. However, Liam supported James and participated in sexually assaulting Elli as a child. Liam was also the Lord who requested that James be killed, which he tries to claim was an effort to help Sin and Elli. However, Sin later discovers that Liam wanted James killed to secure his hold on Asher Corp and to avoid exposure for his abuses. He hides these details from Sin, who ultimately discovers the truth and banishes Liam to Carnage. In addition to abusing Elli, Liam reveals that he has been sleeping with Laura Asher; this indicates his early betrayal of his best friend, Nicholas. Liam, like most of the antagonistic Lord characters, embodies the cold, vicious nature that Elli ascribes to all Lords. His primary motivation is taking control of Asher Corp, a position that would both make him extremely wealthy and improve his already impressive standing within the Lords society.

Liam is punished in two ways, each befitting the ways in which he hurt Sin and Elli. First, his child with Laura becomes Sin and Elli’s adopted child. This precludes the expansion of his status through the pregnancy. Second, the Spade brothers imply that they are sexually abusing Liam at Carnage, mirroring how Liam sexually assaulted Elli years prior. Liam is the only one of Elli’s abusers who survives the novel. He is beaten and sexually violated at the end of the novel, highlighting his role as the mastermind of Elli’s trauma.