Armageddon

The prophets spoke of the day that the world would stand upon a precipice and stare into the abyss. They did not foresee this.
You chant a series of commands, calling upon every favor and every force that you can muster, preparing to break reality. You cannot move while you are casting this spell. Every creature within range knows that you are casting this spell, is aware of the consequences, and is aware of your exact location for the entire time that it is being cast. Choose a point that you can see within range. A 1-mile-radius sphere centered on that point erupts in a singular explosion of unspeakable fire. Any creature, including you, that can see that point at the time that the spell is cast is permanently blinded. Nonmagical structures and objects within the radius are destroyed instantly. Creatures in the radius are knocked prone and take 10d10 force damage, 10d10 radiant damage, and 10d10 fire damage. If they die, they are reduced to ash. A massive crater is carved into the ground, and is left burning with sickening energy. Any creature that starts its turn within the crater takes 2d10 radiant damage and 1d10 fire damage. The crater burns for one month. You immediately gain 5 levels of exhaustion after casting this spell, and if this kills you, you cannot be resurrected by any means.