This curse protects the resting place of a long-dead ruler and punishes any who disturb the ruler's remains or plunder the treasures.
Pronouncement
Carved into the stone of the crypt door are the words "Relentless death follows those who disturb the sovereign's rest."
Burden
Each character that gains the curse is hunted by a wraith that appears at sunset and vanishes at dawn, pursuing the single-minded goal of slaying the cursed individual. The wraith manifests in an unoccupied space within 30 feet of its victim. Destroying the wraith grants a temporary reprieve; it doesn't reform for 10 days. You can scale this curse for lower- and higher-level characters by choosing another kind of creature.
Resolution
The cursed character sets right what they disturbed; stolen treasure must be returned, and if the ruler's body was disturbed, it must be reinterred with proper observances.