Bolas's Citadel (White Border) [MB2 - 39]

Rarity: R #: 39 Creature Type or Sub Type: Legendary Artifact Rules Text Contains: You may look at the top card of your library any time. You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost. T, Sacrifice ten nonland permanents: Each opponent loses 10 life.