Asar is one of the protagonists and point-of-view narrators, as well as the male love interest of the Shadowborn Duet. Though known to most of the world as the infamous Wraith Warden who guards Morthryn prison and its connections to the Underworld, Asar is also the heir to the House of Shadow following the murders of his brother and father. However, he nearly loses this title (and his life) when his sister, Egrette, orders her loyal guard to assassinate Asar.

The Interludes are integral to Asar’s characterization, depicting Asar’s existence as the “product of generations of mistakes” and hinting that he has a unique “way with death” (10). This facility with death was honed in childhood by his brutal mentor, Gideon, but it is also an innate part of him; as he ultimately learns, he is a distant descendant of the god Alarus. Following Alarus’s thwarted resurrection, Asar also possesses a fraction of Alarus’s divinity, making him a threat to the White Pantheon. The failed spell, combined with Mische’s murder of Atroxus, destabilizes the worlds of the living and the dead, forcing Asar to ascend to full godhood in order to save everyone.

Throughout this quest, Asar is preoccupied with the mistakes and regrets of his past. Despite his early childhood dreams of freedom, the only reality that Asar has ever known is being a weapon for others to use. Now that he finally has the power to grasp the freedom that he so desperately desires, Asar must decide how he wants to reinvent himself and what future he wishes to build. The teachings of his childhood mentor and the selfish manipulations of the gods consistently urge Asar to sacrifice everything for power and retribution, but his relationship with Mische counteracts these forces, ultimately saving him from the cold and cruel existence of a god.

Septimus is a minor character who has been present since the start of the series. As one of the princes of the cursed House of Blood, Septimus publicly seeks to regain Nyaxia’s favor for the Bloodborn. Septimus progresses toward this goal by gaining power and acceptance among the House of Night and House of Shadow, yet despite his propensity to offer unexpected help to those in need, everyone regards him with wariness and distrust. That his help rarely comes with a price only garners more suspicion, as his actions are implied to benefit him in some mysterious way that he himself does not reveal.

Septimus’s cunning and knack for strategy, as well as his inclination to participate in bets, games, and bargains, position him as a central character in the series despite his limited narrative time in the first four installments. Though he has explicitly stated that he’s playing a long game, time works against him. The same curse that has driven all Bloodborn vampires to bloodlust and death is beginning to take root in him. The Epilogue, set 10 years in the future, hints at the culmination of this long game he’s been playing. His brief point of view exhibits his detestation of Nyaxia even while he serves her dutifully, his desperation to end the House of Blood’s curse as the condition takes hold of him, and the plans he has for Shiket’s blade of justice.

Vincent is the dead vampire king of the House of Night. The first duology of the Crowns of Nyaxia series depicts him as a ruthless man and complicated father-figure to his daughter, Oraya. His death in the Nightborn Duet is equally complicated, as he leaves many things unresolved with Oraya, who mourns his death and acknowledges his love for her while also recognizing his failures as a father.

Formerly a figure who straddled the line between anti-hero and antagonist, Vincent becomes a full-fledged ally and mentor to Mische as he ushers her from the underworld and guides her on her mission. Though he claims to be motivated by a desire to save the House of Night, it becomes clear that he primarily wants to ensure the survival and well-being of his daughter. Mische is initially distrustful of his intentions: “Vincent was a vampire king. And what would any vampire king do to regain their throne after it was snatched away from them so brutally? What would any vampire king do for revenge?” (28). The world they inhabit is so focused on revenge and retribution that good intentions are rarely taken at face value. In this instance, however, Vincent is acting on pure intentions. Prior to his death, Vincent believed himself akin to a god amongst vampires. Because of this, he believed that he was owed the things he took by force, but this entitlement was a mask for his greedy ambition. Vincent offers a glimpse of someone who has recognized The Perils of Self-Righteousness, contrasting with characters like Shiket, her Sentinels, and several other gods.

Though a secondary character, Vincent is dynamic. His decision not to use his connection to Mische to mend his fractured relationship with Oraya is selfless and compassionate—a change from his prior ambitious and self-serving tendencies. Though he is laconic about his internal conflict, he inwardly struggles with how to make amends, but eventually, Mische convinces Vincent that the point is to make an effort, as changing the past is impossible anyway. Vincent reaches closure when Mische delivers a handwritten, heartfelt letter to Oraya on his behalf.

Shiket, the goddess of justice, is one part of the novel’s collective antagonist, which is nearly the whole of the White Pantheon. Shiket’s voice is described as “vengeful” and “cold,” and she’s depicted as wearing golden armor crafted by Srana, emblazoned with tableaus of her victories enchanted to move in constant battle. Her features are severe—a strong jaw, stern mouth, and aquiline nose—mirroring her self-righteous attitude and uncompromising nature. On her back, she displays six legendary swords that she is rumored to lend to those in need, “with the considerable caveat that the weapon would be destined to one day end them” (42). She also carries the Blade of Retribution, which represents a “rightful death granted in a rightful punishment” and is the sword she used to end Mische’s life (42), earning Asar’s ire and resentment.

Shiket’s unrelenting pursuit of justice knows no mercy, compromise, or compassion, making her an embodiment of the perils of self-righteousness. This attitude extends to her Sentinels, who advocate for the eradication of all vampires, believing them impure, immoral, and unnatural creatures. In their pursuit of justice, the Sentinels commit heinous crimes, believing that the ends justify their means. Shiket and her followers serve as foils to Asar and Mische, who recognize the limits of strict justice and the ethical ambiguities of supposed crimes.