Elemental Vortex

You summon a swirling vortex of elemental energy at a point you can see within range. The vortex is a 10-foot radius cylinder that reaches up to 20 feet high. When the vortex appears, each creature within the area must make a Dexterity saving throw. On a failed save, a creature takes 4d6 lightning damage. On a successful save, the creature takes half as much damage.

At the start of each of your turns, you can move the vortex up to 30 feet in any direction. Any creature that ends its turn within the vortex must make a Dexterity saving throw, taking 2d6 damage of the chosen type on a failed save, or half as much on a successful save.

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