Soul of Thorns by Stacey Trombley

Everything I’ve worked for is within reach. All I have to do is sacrifice my fated mate.
I knew entering the Schorchedlands would mean facing my worst nightmares. But I also knew that if I beat this cursed place— if I could meet terror face to face and survive— I would earn every one of my dreams.
I would be Prince Reveln of the Luminescent Court, savior of the fae realm and the new High Heir. I’d prove my father wrong. I’d live up to my brother’s legacy. I’d gain it all. That was the deal.
But once again, Caelynn has ruined everything.
She’s ruined it by saving me, by sacrificing herself–again. Now that she’s here, it means I can still achieve all of my dreams—I’ll just have to leave her behind in this terrible place along with the wicked souls of fallen fae, and some of the most evil creatures to ever exist.
But I can’t. I can’t live my life knowing she is here, trapped.
So now, not only must I complete my near-impossible task of saving the fae realm, I must also find a way to free Caelynn from the prison she chose for herself. And Caelynn is not the only being trapped within these walls that craves freedom.
We are in the Night Terror’s realm now. And we’re playing her game.