How about a spell for DnD 5e?
Lightning Storm
5th-level evocation
Casting Time: 1 action
Range: Self
Components: V, S
Duration: Instantaneous
You create a 20-foot-radius sphere of crackling energy centered on yourself. You are safe from the effects of the spell, but all other creatures in the area must make a Dexterity saving throw. The creature takes 8d8 lightning damage on a failed save, or half as much damage on a successful one.
At Higher Levels: When you cast this spell using a spell slot of 6th level or higher, the damage increases by 1d8 for each slot level above 5th.