Red and Her Wolf by Marie Hall

When Ewan, a werewolf of the Blackfoot clan, is tasked with killing the Heartsong, he has no doubt he'll be able to carry out his dark master's bidding. Setting out determined to kill the young girl who carries the powers of all fae kind, he never expects to be met with a beautiful face and equally beautiful soul. Knowing he'd much rather claim than kill her, Ewan betrays his clan and risks it all to save Violet. With the evil fae breathing down their neck and a little help from a certain fairy godmother, the two race to find safety and, hopefully, love too. (Kingdom #3)