The area around you is filled with withering magics. If a creature starts its turn within 15 feet of you or enters the area within 15 feet of you, it must make a constitution saving throw. On a failed save, a creature takes 1d4 necrotic damage (increased to 2d4 at level 5, 3d4 at level 11, and 4d4 at level 17) while it takes no damage on a successful save. If a creature fails 3 of these saving throws in the spell's duration, it suffers one level of exhaustion.