Earthshatter

As an action on your turn, you can strike the ground with your maul. When you do so, creatures of your choice within a 60 ft. cone emanating from your maul that are standing on the ground must make a Dexterity saving throw or else be knocked prone and take 2d6 bludgeoning damage. Once you use Earthshatter, you can't do so again until you finish a long rest.