One Silent Night, Paperback/Sherrilyn Kenyon

While the world carries on unawares, Stryker, who leads an army of demons and vampires, is plotting an all out onslaught against his enemies--which, unfortunately for us, includes the entire human race. To avenge his sister, Stryker prepares to annihilate the Dark-Hunters. But things go awry when his oldest enemy returns. Enter his ex-wife. Zephyra. Just when he thought nothing could stop him, he's now embroiled in a centuries old war with a shrew who gives new meaning to pain.