Kelemvor's Boomerang
simple ranged weapon (boomerang), rare, (requires attunement) for special features - see below
A boomerang carved from ivory that feels perpetually cool to the touch, Kelemvor's Boomerang may be used as both a simple melee weapon (1d4 bludgeoning, light, slow) or a simple ranged weapon (1d4 bludgeoning, light, thrown 20/60, slow). If a ranged attack with the boomerang misses, the boomerang returns to the user. In either case (melee or ranged,) the damage counts as magical.
A character may attune to Kelemvor's Boomerang. If attuned, the boomerang gains the returning property, and will return to the user after a ranged attack, regardless of whether the attack hits or misses. While attuned to Kelemvor's Boomerang, a character gains the ability to cast Spare the Dying through the boomerang by touching it to a living creature that has 0 hit points. While attuned, a character may also cast Spare the Dying up to a range of 60ft by throwing the boomerang at a dying target.
Optionally, a character may undergo a ritual that more deeply attunes them to Kelemvor's Boomerang. In addition to taking up an attunement slot, this deeper level of attunement also requires choosing to place some of the user's own life force into the boomerang by sacrificing one of their hit dice (which is then stored in the boomerang until 24 hours after no longer being attuned). While a character has their hit dice stored in the boomerang, the boomerang gains a +1 enhancement bonus to attack rolls and deals an additional +1d4 radiant damage. While a character has their hit dice store in the boomerang, the character also gains the ability to cast Toll the Dead, with the save being based on the user's choice of wisdom or charisma.