Tidal Barrier

A swirling wave of seawater surrounds you, crashing and rolling in a 10-foot radius around your space. The area is difficult terrain, and a creature that starts its turn there or that enters it for the first time on a turn must make a Strength saving throw. On a failed save, the creature is pushed 10 feet away from you and its speed is reduced to 0 until the start of its next turn.