The House of the Three-Headed Dog
An M/M Gothic horror vampire romance
The cover art for The Saint of Heartbreak. A red-filtered image of Gustave Dore art. It depicts the seventh circle of Hell from Dante's inferno. People are twisted in gnarled trees, and harpies, large birds with women's faces, perch on them. Virgil and Dante walk through a clearing, and they are illuminated by a red outline.
Cover by M.E. Morgan
Devon O’Brien has a few secrets: He is an assassin who must find the Crown of the Undying, and he killed the sire of the vampire he must serve.

Living on an isle overtaken by an imperial power, Devon is tasked with traveling to a dreary, peculiar, and seashell-filled coastal manor in Etierre, and he must retrieve a necromantic artifact called the Crown of the Undying from the vampiric lord of the manor, Naberius, who rules over three other vampires. When Devon, undercover, is assigned to serve the fastidious and dry-humored vampire musician Cillian Gallowglass, the two, despite themselves, grow closer and keep each other moored—but never one to let anyone truly know him, he finds himself in a dilemma: Years ago, Devon murdered Cillian’s true sire, and therefore he’s responsible for all the pain Naberius inflicts on Cillian after he took him in. The discovery of that truth may unravel everything, or in their colliding paths toward freedom, penance, and vengeance, Devon and Cillian may find a way to embrace the worst parts of themselves.

The House of the Three-Headed Dog is an M/M dark, sensual, and gothic vampire romance with a trans man assassin lead.
Content Warnings (spoilers)

The House of the Three-Headed Dog has an HEA with the main character and his love interest. However, it also contains strong elements of Gothic horror.

On-page abuse and violence. Sexual slavery. Past mentions of abusive parents. Mentioned imperialism and starvation. Mentioned past rape by deception; an assassin mentions deceiving and seducing his targets before killing them. Coercion, nonconsent, and dubious consent on-page but not primarily between the main characters. The main villain has characters "serve" him with either clear nonconsent or unclear consent/possible vampiric compulsion. Two characters are made to engage in nonconsensual fellatio by a third party. Bloodplay. Vampiric biting and blood-drinking in and out of sexual intercourse. An orphaned character (the MC) recalls dealing with past dehumanization, rape, and underage prostitution for food and money. A trans man contemplates being objectified and fetishized because his identity is seen as a "special asset" or a novelty by others. A trans man menstruates once. Passing, brief mention of an abuser forcing a character to engage in bestiality a thousand years prior.