The Deer and the Dragon by Piper CJ
The deities you call aren't always the ones who answer.
Marlow needs to believe she's crazy. The alternative would mean embracing the giftor curseshared by her mother and grandmother: she can see angels and demons. She would have to admit she's been seeing one for years, the alluring, starlit man she calls Caliban, who understands her, soothes her, loves her like no one else. And with her history of religious trauma, she's far too afraid to do thatat least, until a fae from the Nordic pantheon strolls into her life and informs her that her so-called hallucinations are actually a passionate affair with the Prince of Hell.
A prince who has now gone missing.
But finding Caliban will mean accepting her new reality and seeing the world for what it truly is. The veil is far thinner than she or any human realizes, and the mortal realm is up for grabs. Before she knows it, Marlow is deeply entangled in a centuries-old war, stumbling straight into a battleground between vicious and powerful pantheons. And who will come out on top...may just depend on her and the man she never dared to believe in.