Whenever this creature becomes tapped, exile the top three cards of target opponent's library face down.
You may look at cards exiled with this creature.
, Sacrifice this creature: Turn all cards exiled with this creature face up. Counter all spells with those names.
(01/04/2008)
The only cards you turn face up are the cards exiled with the Grimoire Thief that was sacrificed.
(01/07/2013)
Once a player gains control of Grimoire Thief, that player can look at all cards it exiled, even if those cards were exiled while someone else controlled Grimoire Thief.
(01/07/2013)
Once a player is allowed to look at the exiled face-down cards, that player may continue to do so even after Grimoire Thief leaves the battlefield or another player gains control of it.
(01/04/2008)
The last ability counters all spells on the stack with any of the appropriate names, no matter who controls them.
(01/04/2008)
If a split card is turned face up, the ability counters all spells with the same name as either side of that split card.