You gain a +1 bonus to attack and damage rolls made with this weapon. In addition, while carrying the sword, you have resistance to necrotic damage. Each time you reduce a creature to 0 hit points with this weapon, you can regain 2d8+2 hit points. Each time you regain hit points this way, you must succeed a DC 12 Wisdom saving throw or be incapacitated by terrible visions until the end of your next turn. If you reach your maximum hit points using this effect, you automatically fail the saving throw. As long as you remain cursed, you are unwilling to part with the sword, keeping it within reach at all times. If you have not damaged a creature with this sword within the past 24 hours, you have disadvantage on attack rolls with weapons other than this one as its hunger for blood drives you to slake its thirst.