Zane by Jo Raven

They call me Zen-man, the cool-headed one, the protector. I keep an eye out for everyone, take them in, find them homes. They think I’m the calm and collected one, the self-assured one, the one who knows the way. They think they see me. They think they know me.
But they’re all wrong, because inside I’m broken. I have a jagged hole in my soul I can’t fix, a festering blackness. I’ve been to the pits of hell, and nobody comes back unscathed. Life in foster care fucked me up, and now a thread is all that’s holding me together.
So I sleep around and never date, keeping chicks away. One day I’ll snap, and when I do, there’s no telling who I might take down with me.
All the same, there’s this one girl who won’t be scared away. Dakota. She’s hot, and I won’t deny I want her. But she keeps coming back, pushing me, trying to get me to talk, to open up to her.
She has no idea she’s playing with fire. When the demons come, she’d better be far away from me, just like everyone else.

Standalone novel. No cliffhanger.