Lifestealer

Weapon (shortsword), legendary

Whenever you take the attack action to make an attack with this weapon against a living creature that is not an undead or construct, the target must make a Dexterity saving throw. The DC is 8 + your Dexterity modifier + your proficiency bonus. On a failed saving throw, the target takes 3d8 + 10 necrotic damage. If you use your action to attack with this weapon, you can also use your bonus action to attack with it.