Valkaer's static cloud

You create a 20-foot-radius sphere of static-charged fog centered on a point within range. The sphere spreads around corners, and its area is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. Any creature starting or ending it's turn inside the cloud must make a dexterity saving throw or take 1d6 lightning damage.

If the target is wearing metal armor, they make the save with disadvantage. On a failed save the target takes 2d6 additional lightning damage is unable to take reactions until the end of their next turn. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the radius of the fog increases by 20 feet and the damage increases by 1d6 for each slot level above 3rd.