The Sins of Luther by Ember Michaels

He thought making me pay was the answer.
But he has just as much blood on his hands as I do.
After seven years, Luther Evans came back for me.
He tore my life apart piece by piece, set on evening the score for what I’d done to his sister.
But I had a weapon of my own—the truth, which revealed that Luther isn’t as innocent as he believes he is.
His violence planted a seed of hate.
His callousness pushed me into the same darkness that dwelled inside of him.
And now, I was his perfect little monster to carry out the new part of his plan.
In order to save my own life, I had to make a blood sacrifice.
But I also had a hit list of my own.
The streets of Miami will be stained with blood by the time this is over—and no one would be safe.
Including him.