The Lion and the Deathless Dark by Carissa Broadbent

The Lion and the Deathless Dark is the fifth book in Carissa Broadbent's Crowns of Nyaxia series, and the first of a new duology within it, the Bloodborn Duet. Broadbent is a Sunday Times bestselling romantasy writer, and this opens a fresh chapter with a new couple, so it works as a way in, though longtime readers will get more from it.

The world has spent ten years at war between humans and vampires, under a sky that never lightens. Kyrene is a bounty hunter carrying a blessed sword from the goddess of justice, until grief drives her to a crime that turns both mortals and gods against her. Her only way out is a deal with the enemy: the silver-tongued vampire prince Septimus, who offers her one last job, to hunt and kill the gods themselves. What grows between them is as dangerous as everything they are chasing.

Dark, spicy romantasy for readers of Sarah J. Maas and Rebecca Yarros. Adult, with a slow-burn romance and plenty of blood.