Stifle bersaglia appunto un'abilità, quindi, anche se il permanente che l'ha generata ha protezione dal blu, Stifle se ne fa un baffo e neutralizza l'abilità comunque!
EDIT:
Cita:
Q: I was reading an article at Starcitygames where a guy said in a tournament that he Stifled the activated ability on Goblin Piledriver. Is that a legal move to make, even though the goblin has protection from blue?
A: Goblin Piledriver has a triggered ability, not activated. Once the ability is triggered, it exists independently of the source. The ability itself doesn't have Protection from Blue, so it can indeed be Stifled.
A: Goblin Piledriver has a triggered ability, not activated. Once the ability is triggered, it exists independently of the source. The ability itself doesn't have Protection from Blue, so it can indeed be Stifled.
