You target one creature within 30 feet of you, and that creature must succeed on a constitution saving throw or become afflicted with a necrotic rot that eats them from the inside. On a failed save the creature immediately takes 10d10 necrotic damage. At the start of each of the afflicted creatures' turns it must make a constitution saving throw or take 5d10 necrotic damage on a fail. On a successful save the creature takes half damage and the damage is reduced by one dice.   The creature must continue to make saves until it has succeeded five times, it is targeted by greater restoration or similiar magic or is reduced to zero hit points. A creature reduced to zero hit points by this spell becomes filled with rot and withers away into dust. The creature can be restored to life only by means of a True Resurrection or a wish spell.