Darkest Sin by Sheridan Anne

Thrown in a cage and stripped of my dignity, I was auctioned to the highest bidder, but I never imagined that I’d end my night in the home of Killian DeLorenzo—head of the Romanian Mafia and the most powerful man in the country.
To know him is to fear him, and I just became his newest possession.
Pleasing him comes easily, but what I didn’t expect was the effect he would have on my heart.
This world is no place for a girl like me, and navigating it might just kill me quicker than he ever could. I know I should run, but his vile, wicked ways are a temptation no woman could possibly resist. So I must rise to the occasion—prove once and for all that I have what it takes.
Or die trying.