The Demon Hunters: The Shadow's Prey. The Demon Hunters, #3

[Previously published as Falan by Charity Bishop.]An ancient evil awakens. A city of lost souls cries out. One young investigator must face the darkness that stole his past to save the future. In the rain-slicked streets of 1920s San Francisco, teenage supernatural investigator Falan DuLoc has never met a demon he couldn't handle. With his unique divine authority and the help of his clairvoyant friend, Cassi, he tackles the city's darkest entities with confidence and style.
But when they're called to a routine haunting, they come face-to-face with a malevolent force unlike any they've ever encountered-a violent, powerful spirit that isn't a demon at all. This is no isolated incident. Across the city, the dead are returning. These aren't just harmless specters; they are tormented souls trapped between worlds, heralding the arrival of a far more sinister entity known as the Shadow.
This soul-devouring horror is growing stronger, feeding on the city's despair and preparing to break its barrier into the mortal realm. For Falan, the fight becomes terrifyingly personal when he discovers a link between the Shadow and the tragic death of his mother years ago. Now, Falan, Cassi, and their mentors Byron and Raven are in a desperate race against an ancient darkness. The Shadow needs one final sacrifice to unleash its full power, and it has chosen its victim from among them.
To save his friend and protect San Francisco, Falan must not only confront a god-like entity but also the serpentine demoness who haunts his memories. Can he master his own rage and wield his faith as a weapon, or will the city-and everyone he loves-be consumed by the night?