Bolas’s Citadel

Mana Cost: {3}{B}{B}{B}
Total Cost: 6
Type: Legendary Artifact
Description: 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.
Colors: B