Book The Lion and the Deathless Dark — Carissa Broadbent

Under an eternal night, the world has been ravaged by ten years of war between humans and vampires.
Kyrene scrapes by as a bounty hunter, bearing a blessed sword from the goddess of justice. But in the wake of a devastating loss, Kyrene commits a crime that makes her a target for mortals and gods alike – and she is still desperate for vengeance.
Her only chance at survival – and revenge – is to make a deal with her enemy, the silver-tongued vampire prince, Septimus, who offers her one final job: to slay the gods themselves.
Together, Kyrene and Septimus must hunt the ultimate marks, all while navigating a web of prophecies and curses. Septimus is calculating and mysterious, masking secrets bloodthirsty enough to consume them both. But most dangerous of all is the unexpected kinship Kyrene finds in him.
Kyrene will stop at nothing to fulfil her ultimate goal: to kill the goddess of vampires. Even if it means sacrificing love for revenge . . .