Counsellor by Celia Aaron

In the heart of Louisiana, the most powerful people in the South live behind elegant gates, mossy trees, and pleasant masks. Once every ten years, the pretense falls away and a tournament is held to determine who will rule them. The Acquisition. Now, Sinclair Vinemont is in the running to claim the prize. There is only one way to win, and he has the key to do it — Stella Rousseau, his Acquisition. To save her father, Stella has agreed to become Sinclair's slave for one year. Though she is at the mercy of the cold, treacherous Vinemont, Stella will not go willingly into darkness. As Sinclair and Stella battle against each other and the clock, only one thing is certain: The Acquisition always ends in blood. Full disclosure: This book is a dark romance and is the first of a completed series. TW: SA, suicide.