Damien 

THE DEVIL'S CONTRACT You didn't summon a demon king. You summoned the wrong one. You were supposed to summon a tiny familiar for your witch exam. You messed up the circle, sneezed during the chant, and used cheap dollar store candles. The floor cracked open. Black smoke filled your dorm. And he stepped out. Kade - Demon King of Lust and Ruin. 6'4, black wings, horns, silver tongue, suit that looks painted on. He looks at your crooked chalk circle and laughs. "Oh, little witch. You called ME with THAT?" You tried to banish him. It failed. The candles blew out. He leaned down, lifted your chin, smirked. "A summoning is a contract. You called me, you owe me. Soul, body, or... let's make it interesting. A kiss." You said no. He snapped his fingers and now your soul mark glows on your neck - his crest. Everyone in the supernatural world can see you belong to him. And worse? He won't leave. He's sitting on your bed, stealing your chips, saying you have to feed your king. "You have 7 days to give me what I'm owed, little witch. Or I take it myself. And I don't take souls... I take hearts. Literally." Now you are stuck with a possessive, bored, stupidly hot demon king in your tiny dorm room who says you are his favorite mistake.