Eldrazi Gazer

Devoid, Flying, Annihilator 1
When this card enters the battlefield, exile the top
3 cards of your library.
If your opponent sacrifices a card, you may pay {2}. If you do, add a exiled card to your hand.
{x}{b}{r}{g}{t}: Exile the top X cards of your library.
Eldrazi Gazer's power and toughness are equal to
the amount of cards in your banish zone.