Arcane Atonement

Upon casting this spell, the body of the caster pulsates with a mass amount of arcane energy. The caster has a few moments before all the arcane energy in them, explodes outward. Anyone within 1 mile of the caster must make a WIS save and a DEX save, taking 15d10 Psycic Damage and 15d10 Force damage on a failed save, and half as much on a successful save. This spell also uses any spell slots the caster has yet to use. For each spell slot remaining at the time of casting, an additional 1d10 Psychic damage and 1d10 Force damage is dealt.

This spell immediately atomizes the caster's body. The only way to bring the caster back from this is the wish spell.