Jarrod and the Demon Knight book review

Jarrod and the Demon’s Knight is a solid, well paced gothic paranormal book, featuring enjoyably dark malevolent deities and well designed and used magic system.
The book can be quite dark and unsettling at several times, with multiple scenes dedicated to torturing characters to slow and agonizing deaths as sacrifices to the aforementioned gods. It these scenes, though, that build the grim aesthetics of, and animosity towards, the extra-dimensional monstrous deities our main protagonist confronts throughout the book, as well as their servants. There are several scenes that swing quite lovecraftian in the depiction of these gods and the miracles/rituals they enact. I like dark fantasy, so these scenes, and themes etc worked for me, but they may upset readers who dislike such grim themes.
The other praise I have for the book is the world building/magic system. The story takes place in a multi-dimensional universe and throughout the course of the book we briefly visit several other worlds, ‘Briefly,’ being the operative word there, because while the worlds we visit are cool, we barely spend enough time on them to enjoy the multiple worlds. The world buildings main strength is in the magic system, which is a soft magic system, but with enough of the rules/foundations provided so that the readers can interact with it and understand it. Magic is pulled from the ambient environment and stored in particular metals (called affinity metals, which vary based on user and in quality), which is a simple concept with interplay and lead to the thoroughly enjoyable scene of entering Jarrod’s apartment while in the POV of someone ignorant to the magic and seeing his affinity metal concealed everywhere via metal sculptures and other art forms. There are other times where the author uses the metal basis of the magic system to good effect, but that was my favorite. The other aspect of the magic system is how ones action affect oneself, I.E dark actions blacken the soul and progressively make someone an eviler person, whereas good actions purify the soul. It is a system that allowed for significant interplay because many characters can the see the state of ones soul, and the state of characters souls are often used to narrative purpose, to terrify or shock, etc etc.
The characters are where the book stumbles for me; the side characters are likable enough, with some decent complexity, and Jarrod as well. But I found detective Widcombe difficult to like; she starts the first third of the book as unreasonably aggressive toward Jarrod, and actively persecutes him in her investigation ( a reason is given for this, but still) and she also displays two scenes of sexism (I.E indicating group of men and coworkers and saying they’re bad at their jobs cause they’re men.) Her positive traits mostly boil down to be her tough and determined, and that Jarrod likes her. She’s important to the story as being the outsider to the magical world, but the other characters are just given more interesting narratives: Jarrod with trying to find his found, and the demon’s knight (whose names escapes me ATM) with his fall from grace due to the burning of his family for witchcraft.
The prose is solid and I enjoyed the book as a whole.