Longbow of Lost Souls

Weapon (longbow), very rare (requires attunement) You gain a +1 bonus to attack and damage rolls with this magic weapon. When a wielder attuned to this longbow slays a creature with an arrow shot from it, the soul of the creature it killed is trapped within the mahogany, runescored bow. The creature killed in this manner can't be resurrected. As a bonus action, the wielder can transfer the soul trapped into the bow into an arrow is it is fired. Such an arrow attacks with advantage and does an extra 3d6 necrotic damage on a hit. Once a soul leaves the bow, another can't enter the bow for a full 24 hours. If the wielder attuned to the longbow of lost souls dies while within 10 feet of the bow, the wielder’s soul enters the bow instead. The wielder can't be returned to life until the bow is attuned to a new wielder, and then an arrow can be fired to release the soul.