Apocalypse from the sky

Apocalypse from the sky was a corrupt spell that could only be used for mass destruction.

Effects
The spell caused massive amounts of acid, fire, or concussive force, the caster's choice, to rain down within a certain radius around the caster. This certain radius encompassed 10 miles (16 kilometers) at minimum and increased in more 10 mile-increments with the caster's skill.

The amount of destruction this spell caused, could result in the extinction of an entire population.

The caster wad not safe from this spell.

Components
This spell required somatic, verbal, and material components and incurred a corruption cost. The material component was an artifact. When this spell was cast, one dedicated to the cosmic force of good was used to fuel the spell. The spell's corruption cost was unique as just preparing it was dangerous to the caster's sanity. Actually casting it drove the caster insane while also wracking the body.

While this was not exactly a component, casting the spell took an entire day.

History
Caira Xasten once tried to eradicate Waterdeep in order to draw Atropus to Toril to end the world. The artifact she intended to fuel the apocalypse from the sky spell with was the  book of vile darkness.