Tesla's Sphere

A sphere-shaped wall of lighting plasma appears around you with a radius of 5 to 20 feet. You can pick any radius in that range when you cast the spell, and may not alter it later. Creatures passing through the wall must make a Constitution saving throw or take 6d6 lightning damage and have their movement slowed for two rounds. Those who save, take half the damage and do not suffer reduced movement. You may designate up to six creatures for whom a door opens around them as they pass through. Missile fire attacks made against the caster from outside the sphere are made at disadvantage.

At Higher Levels. When you cast this spell using a spell slot of 6h level or higher, the damage increases by 1d6 for each slot level above 5th.