Countervailing Winds
Instant
Counter target spell unless its controller pays 
for each card in your graveyard.
Cycling (, Discard this card: Draw a card.)
The Eternals had long since mastered every technique taught during the trials.
Tyler Jacobson
Rulings
Count the number of cards in your graveyard as Countervailing Winds resolves to determine how much mana the controller of the target spell must pay to avoid the spell being countered. Countervailing Winds is still on the stack at this time and won’t count toward this number.
(wotc • 2017-07-14)
Rulings
Count the number of cards in your graveyard as Countervailing Winds resolves to determine how much mana the controller of the target spell must pay to avoid the spell being countered. Countervailing Winds is still on the stack at this time and won’t count toward this number.
(wotc • 2017-07-14)