Soulshard Phylactery

This small, dark crystal appears to pulse with a faint, otherworldly glow. When held, it grants the user advantage on saving throws against being frightened or charmed. Once per long rest, the wielder can expend a charge to siphon a fragment of life from a creature within 30 feet that they can see. The target must make a Constitution saving throw (DC 13) or take 2d6 necrotic damage, while the wielder heals for half the amount of damage done. However, each use taints the wielder's soul slightly; after using the ability three times, the user experiences nightmares, imposing disadvantage on Wisdom saving throws until they complete a long rest. The Soulshard Phylactery is often thought to be a fragment of the Soul Reaver's own essence, twisted by its connection to lost souls. It is said that they were created from the obsidian shards of fallen creatures that the Soul Reaver devoured, resonating with the remnants of their souls. The thrill of siphoning energy from the living can be intoxicating, yet each use further binds the user to the encroaching darkness of the undead.