Baneful Omen
From Rise of the Eldrazi set
Baneful Omen
Enchantment
At the beginning of your end step, you may reveal the top card of your library. If you do, each opponent loses life equal to that card's mana value.
At the beginning of your end step, you may reveal the top card of your library. If you do, each opponent loses life equal to that card's mana value.
