Earthshatter

Your fury knows no bounds. As an action, you can slam the ground in front of you, sundering it  in two. Each creature in a 15-foot cube originating from you must make a Dexterity saving throw. On a failure, the creature takes 2d8 bludgeoning damage and is knocked prone. On a success, the creature takes half damage and remains on their feet. If the terrain is breakable, it will be destroyed and become difficult.