Seventh Son (book)
Seventh sons have strong "knacks" (special powers), and seventh sons of seventh sons are both very rare and vert owerful. In fact, the young Alvin appears to be the only one to be currently in the world, and the only other one who known to have ever existed turned water into wine. Alvin's powers make him the target of the Unmaker, which recognizes Alvin's powers as those of a Maker, who can build and change things, and so the Unmaker tries to kill him.