Cleave

You've learned to put the weight of a weapon to your advantage, letting its momentum empower your strikes. You gain the following benefits:

• On your turn, when you kill an opponent you gain an immediate attack to any enemy within 5 feat.
• Before you make a melee attack with a heavy weapon that you are proficient with, you can choose to take a -1 to a -5 penalty to the attack roll. If the attack hits, you add +2 damage per -1 to the attack's penalty.