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, ending the effect on itself on a success.
Hits deal an extra 2d6 necrotic; DC 15 CON save or the target can't regain Hit Points for 1 hour, repeating the save at the end of each of its turns.
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.