Thaelun's Magnet Sphere

You create an orb of electricity that acts as a tesla coil, electrocuting anything within its radius. The sphere has a diameter of 5 feet but can damage creatures up to 20 feet away from it. When summoned, any creature within the sphere's range must make a Dexterity saving throw. On a failed save, a creature takes 4d6 lightning damage, or half as much damage on a successful save. Any creature within the actual tesla (the center of the sphere) has disadvantage on its saving throw.

Additionally, as a bonus action you may move the sphere 15 feet. 

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.