The Demon Queen Trials Series by C.N. Crawford

I never thought I'd be singing happy birthday to myself in a dungeon. And yet when a sinfully sexy demon crashes happy hour, that's exactly what happens. He’s known as the Lord of Chaos, he’s mistaken me for my succubus doppelgänger. Happy birthday to me.When he tastes my blood, he finally understands I’m mortal. And I realize we have something in common: we both crave revenge. So we make a deal: I can stay in the forbidden city to hunt for my mom's killer... moreI never thought I'd be singing happy birthday to myself in a dungeon. And yet when a sinfully sexy demon crashes happy hour, that's exactly what happens. He’s known as the Lord of Chaos, he’s mistaken me for my succubus doppelgänger. Happy birthday to me.When he tastes my blood, he finally understands I’m mortal. And I realize we have something in common: we both crave revenge. So we make a deal: I can stay in the forbidden city to hunt for my mom's killer. In return, I’ll help him get the vengeance he craves. I just have to pose as a sexy succubus. One problem--he's my number one suspect. And that’s increasingly hard to remember as he teaches me my role: seduction. With each heated touch I drift further into peril. And if I fall under his seductive spell, death awaits me. "I flew through this book... Hot demon lord—check, action—check, romance—check. And there's spice! If you love my books, you definitely want to read this one." -- Laura Thalassa less

Once, I was a broke college student. Now, it seems I'm destined to rule as the Lightbringer--queen of the demon realm. Except I have competition in the form of Orion, the Lord of Chaos. Like me, he has been marked as a leader. We can't keep our hands off each other, even if he swore an oath to kill me.It seems we both want the same thing--the crown. And in this battle of wills, only one of us will be left standing.

In a series of trials, Rowan and Orion battle for the throne in the City of Thorns.