Castle Vrul

{t}: Add {w}{b},{w}{w},or {b}{b} to your mana pool.

Defender, flying

Whenever you gain 10 or more life this turn,
Floating Castle of Vrul loses defender and gains
+10/+0 until the end of turn.

{5}{w/b}{w/b}{w/b},{t}: You gain 10 life.