Bolt of Ruin

Channeling the pure energy of the untamed tempests, you conjure a bolt of lightning in your grasp and throw it at a location within the spell's range, causing a calamitous lightning strike. Each creature within 40 feet of the location you choose must make a Dexterity saving throw or take 12d10 lightning damage, taking half that on a successful save. You are immune to damage from your own casting of this spell, and each creature of your choice has advantage on the saving throw.

When you cast this spell, you may charge it for up to one minute, holding back it's effects and entering concentration to do so. For every round you concentrate on charging the spell, the area of effect and range increase by 10 feet and the damage increases by 2d10. If your concentration is broken the spell is immediately cast centered on you, and you lose your immunity the spell's effects.