Temporal Desecration

You reach into the target's timeline and destroy it, aging them by 1d4 years for each 10 points of damage they take.

A creature targeted by this spell must make a Constitution saving throw. On a failed save, the target takes 10d6+40 force damage. The target ages rapidly, their body withering and turning to dust if this damage leaves them with 0 hit points.

If the target survives the spell, their age stays at the new number. A Wish spell or a true resurrection spell after the target has died will return them to their natural age. If the number of years they age is past their race's expected life span, that creature must make a separate con save (dc 10) to see if they pass away from old age.