Artillery War Storm

You launch several lightning bolts centered on a point in range. The ice freezes a 60-foot radius and every creature not immune to lightning must make a Dexterity saving throw. A fail takes 9d8 lightning damage on a failed save, or half as much damage on a successful one. all creatures take half taken damage at the start of their next turn.

You burn a 1st level spell slot every other casting.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage is increased by 2d8 for each slot level above 6th.