Arc Dome

A done of electric energy 20 ft in diameter emits from the caster. While this spell is active the caster and anyone within 40 ft of the caster are deafened by the bolts of lightning. Any creature that is within must make a Dex saving throw equal or greater than the casters save DC. On a failed save they take 5d6 lightning damage or half on a successful save. Any creature that enters the dome immediately takes 3d6 lightning damage and if they start their turn in the dome take an additional 1d6 lightning damage until they leave or the spell ends

The spell has no effect on the caster so long as they maintain contact with the metal rod.