Promise of Phyrexia

Compleation — If you control a Swamp, you may remove two poison counters from an opponent rather than pay this spell's mana cost.

Choose a nonland card name. If no mana was spent
to cast this, target opponent reveals their hand and discards all cards with that name. Otherwise, reveal cards from the top of your library until you reveal a card with that name, put that card into your hand, and exile the rest.