Thrashing Earth

You point to a spot within range and animate the ground to begin lashing out at anyone within range. The area begins as a 5 foot square only effecting solid surfaces within its area of effect. Any creature starting their turn standing on the cluster or moving onto it must make a Dexterity saving throw, taking 6d8 bludgeoning damage on a failure or half as much on a success.

At the end of each of your turns, the area of effect expands by 10 feet. Once the cluster expands to a 35 foot square, it remains that size for the rest of the duration so long as you hold concentration. The growth extends up, down, and around walls. Walking through the cluster counts as difficult terrain.