Year 1: Renegade: A supernatural academy book for teens (Guardian Angel Academy)

Evil exists. I know—I was created from it.
Most students at Guardian Angel Academy lived a good, possibly boring life on earth before their untimely deaths, which landed them at the academy, learning how to be good guardians for the hapless mortals still breathing.
Not me. My time on earth was spent as a servant of darkness, performing acts unmentionable to the undefiled ears of the angels at the academy.
But somehow, I was given a chance at redemption. Somehow, I got enrolled here. And somehow, I have to prove myself worthy of my angel wings.
Or I'll get sent back where I came from.
Now if I can just survive the weapons instructor determined to find me guilty of demonry, the mysterious dark angel who won't get out of my thoughts, and the hot-as-you-know-where angel who hates my guts because of who I am.
There is just one small problem . . .
I made a promise. A promise to the lord of the devils. If I keep it, my soul is forever damned.
But if I break it, I will be destroyed.
Welcome to Guardian Angel Academy.