House of the dead duology

Seventeen-year-old failed ghost-fighting warrior, Wren, journeys to the haunted wasteland of the Breach to rescue a kidnapped prince and must team up with the very person responsible for the kidnapping. In the Dominions, the dead linger, violent and unpredictable, unless a bonesmith severs the ghost from its earthly remains. For bonesmith Wren, becoming a valkyr--a ghost-fighting warrior--is a chance to solidify her place in the noble House of Bone...