Assassin’s Blade

Weapon (shortsword), very rare (requires attunement)

When you hit with an attack roll using this magic shortsword, the creature takes an extra 1d6 necrotic damage and it can’t regain hit points until the start of your next turn.

Life Drain. When you hit a creature with this shortsword, you can force that creature to make a DC 15 Constitution saving throw. On a failure, the creature suffers 1 level of exhaustion and is paralyzed for 1 minute. The creature can repeat the saving throw at the end of each of its turns and whenever it takes damage, ending the effect on a success. While the target is paralyzed this way, you can use an action on each of your turns to cause it to suffer 1 level of exhaustion and you regain 4d6 hit points. The effect ends if the target dies, if you use your action to do anything else, or if you or the shortsword is ever more than 5 feet away from the target. Once used, this property can’t be used again until the next dawn.