Sword of Wounding

Weapon (any sword or Glaive), rare (requires attunement)

When you hit a creature with an attack using this magic weapon, the target takes an extra 2d6 Necrotic damage and must succeed on a DC 15 Constitution saving throw or be unable to regain Hit Points for 1 hour. The target repeats the save at the end of each of its turns, endign the effect on itself on a success.