Murder once seen The oddities series, book 1.

In the city of Nis, things often aren't what they seem. Derwin is a bounty hunter gifted with the Oddity of superhuman strength and agility - perfect for hunting down fugitives and demons who roam the streets. One killed his boyfriend two years ago, and Derwin won't stop until he finds out who. Police suspect it was someone he sent to prison, but he can't shake the idea that they're missing something. Elliot is a rentboy who's been living on...