Of Salt and Wine
Soren's story starts with Jack, an abusive teacher that communicates in dream. When a priest asks for help removing a demon in his church, Soren takes the opportunity to step out from under the shadow's shadow to make a name for himself. Only one demon turns into four, and they requested his presence in the first place. ReligioUrban Fantasy with elements of horror.
A crossbreed of urban fantasy and gothic horror, Soren fights a threefold battle: his shade of a tutor, Jack; a legion of four demons; the post traumatic stress of losing loved ones. With a proverbial multitool and a roll of magical duct tape, Soren is a Macgyver of magic. He has his own tricks, he has his own skills, and he somehow manages to trap an ancient creature in his walking stick.
Similar novels would include Dresden Files and Carrion Comfort by Dan Simmons.