Wave Breaker

Choose a point within range. When you cast this spell, and then as a bonus action on each of your turns until the spell ends, you force all creatures within a 15-foot-radius sphere of the chosen point to make a Dexterity saving throw. On a failed save, a creature takes 5d6 force damage and their movement is halved until the start of your next turn.

At Higher Levels. When you cast this spell at 3rd level or higher, the sphere's radius increases by 5 feet for every spell slot level above 2nd.