Eldritch Maelstrom of Disintegration

You unleash a chaotic and uncontrollable pulse of dark eldritch energy that creates a large ball of crackling force and lightning surges from you in a 30 ft sphere. All creatures within range must make a Dexterity saving throw. On a failed save, they take 8d10 force damage, an additional dealing 8d6 lightning, and are pushed 30 feet closer and knocked prone. If this damage reduces the target to 0 hit points, it is disintegrated. A disintegrated creature and everything it is wearing and carrying, except magic items, are reduced to a pile of fine gray dust. The creature can be restored to life only by means of a true resurrection or a wish spell. 

When you cast this spell using a spell slot of 7th level or higher, the damage increases by 2d10 force damage and 2d6 lighting damage for each slot level above 6th,

(this spell is instant and doesn't last one minute but it wont let me change it)