These monstrous gods

"To cage a god is divine. To be divine is to rule. To rule is to destroy. Using ancient secrets, Galina and Sera's mother grafted gods into their bones. Bound to brutal deities and granted forbidden power no commoner has held in millennia, the sisters have grown up to become living weapons. Raised to overthrow an empire - no matter the cost. With their mother gone and their country on the brink of war, it falls to the sisters to take the helm of rebellion...