D.O.O.M; Destro Omnipotence, Oppenheimer's Masterpiece

Blazing orbs of black and green flame plummet to the ground at two different points within visual range of the caster. Each creature in a 60-foot-radius sphere centered on each point you choose must make a Dexterity saving throw. The sphere spreads around corners. A creature takes 15d6 radiant damage, 15d6 necrotic damage, and 15d6 fire damage on a failed save, or half as much damage on a successful one. A creature in the area of more than one fiery burst is affected only once.

The spell damages objects in the area and ignites flammable objects that aren't being worn or carried. The areas effected by this spell will be unable to naturally grow plant life and will be covered in a poisonous mist for a period of 25 years, making the area uninhabitable by mortal creatures.