The Demon of Beausoleil by Mari Costa
Oni Press (January 27, 2026)
Reviewed by Joshua Gage
Mariana Costa was born in Brazil (allegedly) fully formed from a hole in the ground. She is a deeply unserious creature who eats stories and then spits out new ones to repopulate the ecosystem. Whether these new stories are better or worse is for you to decide by eating them yourself. She is best known for Peritale, Paranorthern, Belle of the Ball, and Life of Melody. Her newest graphic novel is The Demon of Beausoleil, which an exciting queer romance set against a background of historical horror.
The book is set in a pseudo-Victorian era. The protagonist, Helianthes, is a Cambion, which means he was born touched by demons. With his horns, claws, and tail, Helianthes is a precocious exorcist whose attitude and propensity for seduction has succeeded in alienating those closest to him, all save for his long-suffering bodyguard, Elias, who sees him as less a strange, mythical being and more just a tiresome nuisance to keep an eye on. Together, the two venture into the streets to exorcise demons for fun and profit. But as Hell becomes increasingly drawn to his enigmatic bodyguard, and as Elias becomes increasingly aware of his feelings in return, the two find themselves faced with a growing, chaotic dark that might threaten everything they’ve been working toward.
Mari Costa has written a raunchy queer romantasy. Helianthes’s half-demon status and society’s reaction to it serve as a commentary on queer identity. Elias’s growing emotions and the complications they cause in a relationship between bodyguard and half-demon exorcist is a beautiful character arc, and the flirtations between the two characters are as charmingly awkward and seductively fun as a reader would want in a book like this.
Costa has written a sexy mature tale full of action, violence, and romance. While this book is certainly for Mature Audiences Only, eroticism is only a part of the tale. The horror, both in terms of society’s view of Helianthes as a Cambion, as well as the ever-growing threat he and Elias must face together, is well-balanced against the lustful romance of the plot. The Demon of Beausoleil is strongly recommended for mature readers of romantic horror.
