Pouncing Raptor

First Strike, Magnitude 2 (If you pay {2} when casting this spell, it can't countered or targeted of a spell or ability an opponent controls on the battlefield unless that player pays {2} or the effect is countered. Put two +1/+1 counters on it when it enters the battlefield.)
Each creature you control wth a +1/+1 counter on it has Pounce (Whenever this creature blocks or becomes blocked by a creature, that creature loses first strike and double strike until end of turn.)