It That Can See

On your attack phase you may tap any
amount of creatures. If you do, add +0/+1 counters to It that can see equal to each creatures power. At any time you may tap It That Can See to add +1/+1 counters to a creature equal to the toughness of It That Can See. These +1/+1 counters are removed at the end of the turn.

It That Can See is not affected by all spells
that would change It's toughness.