Doom of Ancient Decrepitude

You generate an entropic field that rapidly ages every creature in the area of effect. The field covers a sphere with a 20-foot radius centered on you. Every creature inside the sphere when it's created, including you, must make a successful Constitution saving throw or gain 2 levels of exhaustion from sudden, traumatic aging. A creature that ends its turn in the field must repeat the saving throw, gaining 1 level of exhaustion per subsequent failure. You have advantage on these saving throws. An affected creature sheds 1 level of exhaustion at the end of its turn, if it started the turn outside the spell's area of effect (or the spell has ended). Only 1 level of exhaustion can be removed this way; all remaining levels are removed when the creature completes a short or long rest. A creature that died from gaining 6 levels of exhaustion, however, remains dead.