Spiritskin

Wondrous item, legendary (requires attunement)

This fragile looking garment, appears wispy and light, full of lace and sheer areas. It also seems to pulse and surge with random waves of pulsing, yet faint, lights.

While the spiritskin is on your person, when you deal damage to a creature with a weapon attack, its hit point maximum is reduced by an amount equal to the damage dealt. This reduction lasts for 12 hours. A creature reduced to 0 hit points by this reduction dies instantly. Additionally, as a reaction when a creature you can see within 60 feet of you is slain, you can transfer the creature’s soul into the spiritskin. A creature whose soul is trapped within the spiritskin cannot be returned to life without a direct act of divine intervention or by freeing it. Each soul within the spiritskin serves as an infinite source of water, flavored by the many unique aspects of its life that gave its soul shape. Destroying the spiritskin frees all souls trapped within.