Chronal Rift

You tear open a temporal rift at a point you can see within range. Each creature in a 20-foot radius sphere centered on that point must make a Dexterity saving throw against your spell save DC. On a failed save, a creature takes 6d6 force damage and its speed is reduced to 0 until the start of your next turn as it gets caught in the turbulent temporal energies. If they succeed the saving throw they only take half damage and no additional effects. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.