Lord of Winter by Ana Calin

Fae law is clear—Never use magic in the mortal realm. Except that’s what I do for a living, and for paying off my student debt. I just couldn’t leave it on Aunt Miriam’s tired, battered shoulders, not to mention that love spells pay well. And it all worked out just fine—until it didn’t, and the Lord of Winter tracked me down.
Lysander Nightfrost is a ruthless fae king enforcing millennia old law. I should run for the hills when he appears, but my feet keep rooted in the ground. I can’t stop staring at his sharp warrior features, his hair like liquid gold, his ice-blue eyes sending chills all through me. He’s here to punish me. But when he learns who I really am, the tides turn.
I am what the fire king Xerxes has been searching for since the day my father died, which makes me a powerful weapon in Lysander’s hands. One of the ways he can use me is trade me over in exchange for something he wants from Xerxes. I’m trapped, stripped of choices, but not of my will. If I go down, I’ll take Lysander’s ice-cold heart with me. It’s a tough game, but I will either melt it, or drown it at the bottom of the ocean.