Bolas's Citadel 79 - Promo Pack: Theros Beyond Death [PPTHB]

Bolas's Citadel

You may look at the top card of your library any time.
You may play the top card 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.

• Set: Promo Pack: Theros Beyond Death
• Rarity: Rare