Tamper with Fate

When Tamper with Fate enters the battlefield,
exile the top three cards of target player's library
face down. You may look at cards exiled this way.
Sacrifice Tamper with Fate: turn all cards exiled
with Tamper with Fate face up, then counter
target spell with the same name as a card turned
face up this way.
"Snuff out all rivals to our power, even those unborn."
—Sivique, Lady of Darkness