Kingdom of Villains by Ella Fields

When a faerie princess with a curiosity for things better left alone encounters a dark fae prince with a beastly secret, she’s forced to become his bride in a dangerous new world where love and loathing struggle to coexist…
I’d known exactly who he was—the Unseelie prince. But I hadn’t known just what he was.
I’d been fooled.
The creature I’d formed a tentative friendship with in my family’s dungeon was not the gentle, intriguing prince I’d thought him to be.
He was a monster. A bloodthirsty beast.
And I’d helped him escape my uncle’s clutches.
Such a betrayal called for severe consequences, and the price of releasing the biggest threat our kingdom had faced in hundreds of years was not one I would survive.
But upon discovering my uncle’s foiled plans for their prince, the Unseelie demanded vengeance, and an agreement was made.
My savior and my doom returned, and this time, he wasn’t leaving without me.
Regardless of how I loathed him, the deceitful and dangerous male was my last hope. Yet when he looked at me, touched me, dared to love me, the beliefs I’d worn as armor began to melt.
I couldn’t let that happen.
Though avoiding fate would prove impossible when the only way to save my life was to surrender it by marrying the monster who’d destroyed it.