Lover enshrined - J. R. Ward

Phury, Zsadist's twin brother and a vampire in the Black Dagger Brotherhood, makes the ultimate sacrifice and stands in for a fellow brother to become the chosen - one who will save the brotherhood's bloodlines. Tormented by the love he has for his twin's mate, he devotes his passion to the higher good of his race and forbids himself from being distracted by a romantic relationship. The war with the Lessening society is graver than ever, and the brothers need the few warriors they have to fight. Phury is resigned never to divert himself with love or put his brothers in jeopardy, until he comes face to face with the only woman who can tempt his heart and make him question his chosen destiny...