Confederacy's Fortress

{t}: Add one mana of any color. Activate only while Confederacy's Fortress is a land.
Facedown creatures you control have Prowess.
As long as Confederacy's Fortress is your active
plane, during your endstep, blur the top card of
your library. Then put a +1/+1 counter onto all
facedown creatures that entered the battlefield
under your control this turn.