Wayward

Born without magic, seventeen-year-old Helena “Hex” Wayward is an embarrassment to her power-hungry relatives. As the weakest member of the world’s most deadly magical family, Hex learns early how to avoid confrontation. There’s no defending herself against an errant curse or the pit-demon that her cousins like to summon during family reunions. When the dark magic inside of her -- magic that she never dreamt even existed -- erupts in a violent display, it kills a member of a rival family. Now, Hex's family hopes to use her magic for their own sinister purposes and their enemies just want her dead. Abandoning her magic will leave her defenseless but Hex knows how quickly power corrupts even the best intentions. Hex has to make a choice: Save her life or save her soul.