Six Deadly Steps by Sonya Jesus

She’s willing to start a war for love.

Appointed his sister’s handler, Luca’s done nothing more than tread the fine line between dutiful son and loyal informant, but he’s tired of being in a world where he doesn’t belong, doing things he hates. Torture, blood lust, and power are the Cabralis’ motto, but Luca wasn’t made that way. The girl he loves, however, that’s a different story.
Isabella may not be as twisted as Luca’s sister, but she’s smart, rich, and ruthless… Rebellious at heart, Isabella’s wild spirit got her kicked out of boarding school. Forced to live with the father she despises and abide by his rules, Isabella is placed on house-arrest for her own safety. Years later, she decides marrying her father’s right-hand man will ensure her freedom.
That is until she finds out everything was a lie. She was nothing more than a piece in her father’s game. Now, she’ll do anything to escape and find her way back to Luca, even if it means starting a war.