Nine Lives Stealer

You gain a +2 bonus to attack and damage rolls made with this magic weapon. The sword has 1d8 + 1 charges. If you score a critical hit against a creature that has fewer than 100 hit points, it must succeed on a DC 15 Constitution saving throw or be slain instantly as the sword tears its life force from its body (a construct or an undead is immune). The sword loses 1 charge if the creature is slain. When the sword has no charges remaining, it loses this property.

You gain a +2 bonus to attack rolls and damage rolls made with this magic weapon. Life Stealing. The weapon has 1d8 + 1 charges. When you attack a creature that has fewer than 100 Hit Points with this weapon and roll a 20 on the d20 for the attack roll, the creature must succeed on a DC 15 Constitution saving throw or be slain instantly as the sword tears its life force from its body. Constructs and Undead succeed on the save automatically. The weapon loses 1 charge if the creature is slain. When the weapon has no charges remaining, it loses this property.