Tyxur, Dragon King

+3: Until you put down your next land your creatures and Planeswalkers can't be affected by other players, creatures and Planeswalkers.
-X: Deal X damage to target player, Search your library for a creature or Planeswalker.
-12: If there is a dragon in the grave then "put all dragons in your library, hand, grave and exile onto the battlefield, gain a life for each dragon.