Waves of Destruction

You unleash your fury, creating waves of fiery destructive energy that ripples outward from you. Each creature you choose within 30 feet of you must succeed on a Constitution saving throw or take 5d6 force damage, as well as 5d6 fire, and be knocked prone. A creature that succeeds on its saving throw takes half as much damage and isn’t knocked prone. Any creature that is left with 0 hits points from this damage is turned into ash.

On each of your turns until the spell ends, you can use your action to unleash another wave of destruction. 

When a creature is destroyed by this spell, everything it is wearing/carrying, except magic items, are reduced to a pile of fine ash. The creature can be restored to life only by means of a true resurrection or a wish spell.