Carrion King

If you control 4 or more creatures, you may sacrifice all creatures you control rather than pay Carrion King's mana cost.
Infuse 2 {b}{b}{b} (If this creature isn't infused, it gets 2 +1/+1 counters and gains haste until end of turn.)
When you infuse Carrion King, if an opponent controls no creatures, it can't attack until end of turn.