2024 rules reference for Sword of Wounding.
Weapon (Glaive, Greatsword, Longsword, Rapier, Scimitar, or Shortsword)
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 15Constitution 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, ending the effect on itself on a success.