Bolas's Citadel {3}{B}{B}{B}

Legendary Artifact

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 converted mana cost rather than pay its mana cost.

{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Illustrated by Jonas De Ro