Alfax, the Nature Seer

As long as Alfax, the Nature Seer is in the
command zone, creatures you control have
"{t}: Add X mana of any color to your mana pool,
where X is the number of times Alfax has been
in the command zone this game. Scry 1. If this
mana is used to cast a creature with power 4 or
greater, draw a card instead."
Creatures you control with power 4 or greater get
+2/+2 and can't be blocked.