Cleave

You have learned to follow through effectively with your most powerful blows. You gain the following benefits while wielding a weapon with two hands:

When you score a critical hit, you may pick another target within your reach.  Make an attack roll with disadvantage against that target. 

When you reduce a target to 0 HP, and the damage you dealt was higher than the remaining HP of the target before the attack, you may target any number of creatures within your reach to take damage equal to the difference.