Text (CS+errata): 1/1. ; {2}, Reveal X blue cards from your hand, Sacrifice ~this~: Counter target spell unless its controller pays {X}. [Oracle 2009/07/08]
A card that is revealed stays revealed until the ability leaves the stack, or until it leaves your hand. [Coldsnap FAQ 2006/06/14]
An already revealed card can be used to pay the cost. [Coldsnap FAQ 2006/06/14]
