Aro has been cast for New Moon. Michael Sheen has been added to the cast of the Twilight sequel New Moon. He'll play Aro, the leader of the Volturi, director Chris Weitz confirms to The Daily Mail. The actor was "aggressively" pursued, Weitz added. "Michael's role is so important because he's the head of all vampires. Aro is, on the surface, a very gracious and friendly vampire, but beneath that he is a tremendous threat." Sheen should be at home in the fantasy realm: He played the Lycan (or werewolf) Lucian in the Underworld films.