[Radek]

(1) Vampires aren't undeads in W&W. Get the Crusade trait and kill a vampire. You get the same amount of XP as without the trait.
(2) The Vampire Ring is given by Adrianna in the Skull Castle. The only way of getting the ring is completing her quest and choosing the ring for your reward. You need not become a vampire when you ask the ring. The Vampire Ring looks like a Bat Ring but it is far more expensive. If you have sold it unwillingly then check the shop where you have sold it. You can buy it back.