Tainted Adversary

Deathtouch When Tainted Adversary enters the battlefield, you may pay 2B any number of times. When you may this cost one or more times, put that many +1/+1 counters on Tainted Adversary, then create twice that many 2/2 black Zombie creature tokens with decayed. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)