Higher Demon by Louisa Masters

No matter the demon, the hunter’s role is clear…

A thousand years ago, my great-something uncle founded the Collective, a secret organization dedicated to protecting humanity from demons. The hunter tradition has been passed down over the generations, from parent to child, secure in the knowledge that the Collective is a community of safety and knowledge.
But betrayal sucks, and six years ago, it turned my world—and the Collective—upside down. After generations of deception, the hunters left behind are picking up the pieces and trying something we’ve never done before—working side by side with our enemy.
Demons, just to be clear. They’re apparently “misunderstood,” but the jury is still out on that. And I—a twentysomething archivist with an addiction to hoodies—somehow ended up as liaison to the demon ambassador.
If it sounds like a nightmare, that’s because it is. The demon ambassador is a stuck-up, pretentious twat… not to mention he could kill me with a thought. Worst of all, he’s getting under my skin in ways I never expected. But I’m the only hunter who doesn’t actively want to kill him, so… tag, I’m it.
I’ve already been betrayed by those I should have been able to trust the most. How hard can hanging out with a higher demon be?

The author recommends reading the Ghostly Guardian series for full background on what happened six years ago, though it’s not essential.