Detonation

You conjure the mightiest magics in existence to utterly annihilate a devastating area and leave the land inhospitable. Choose a point you can see within range. Each creature in an 1-mile-radius sphere centered on the point you chose must make a Dexterity saving throw. A creature takes 100d6 force damage and 100d6 radiant damage on a failed save, or half as much damage on a successful one.

For then next 10 days, each creature that enters the area for the first time on a turn or starts its turn there takes 5d10 radiant damage and suffers a level of exhaustion.

The explosion spreads around corners, and creatures in the sphere gain no benefit from cover for this saving throw. This spell damages objects in the area, and all force damage dealt to objects in the area is doubled.