Wintersfall. Gen-Heirs: The Guardians of Sziveria, #1

Katria Nachemir, the daughter of a professional assassin, agrees to work for the First Intelligence Office in exchange for a deeper investigation into the deaths of her mother and sister. Her inherited skill with a gun and precise knowledge of its use make her a valuable asset to the Sziverian government. Yet she never expected to find herself under the care and protection of a handsome stranger. Haunted by a dark family history, Sean Blackbain escapes the negative rumors by leading an intel guardian team, including the young and dangerously beautiful Katria.
But when a botched assignment forces the team home, Sean and Katria discover the contracts they signed three years ago were for more than just employment. The government they trusted had arranged their marriage. Suddenly, the glittering and deceptive world of the ranked guardian society replaces the dangers of dark alleys and secret missions. As a Sympath, Sean absorbs the emotional states of everyone around him, especially the desire his new wife is determined to embrace, much to his frustration.
He knows he's the last man she should want, let alone be married to, yet resisting their attraction is impossible. Sean soon finds himself willing to do anything to protect her. But keeping Katria safe proves far more difficult than he ever imagined. The deeper she digs into the murders, the more danger relentlessly finds her.