Golden Funeral Mask of the Gray Merchant

Wondrous item, legendary (requires attunement) Price: 80,000-100,000 gp | medium sentimentality

This mask holds an unlimited number of charges to fuel its magic. It loses all charges when a new creature attunes to it. While you wear the mask, you add 1 charge to the mask every time a creature with an Intelligence score of 8 or higher dies within 30 feet of you, capturing a small part of the creature’s life essence but not its soul. While you wear the mask, you can consume charges to perform the following actions: regain expended hit dice (1 charge per die), cast vampiric touch (2 charges plus 1 charge per level to cast the spell at higher than 3rd level), cast lesser restoration (2 charges), cast greater restoration (5 charges), or cast heal (6 charges).

Paid

While you wear the mask, you can use an action to consume 10 charges to cast mass heal.

Overpaid

You can use an action to summon the Gray Merchant to visit you, but doing so destroys the mask, causing it to dissipate into black smoke. The Gray Merchant arrives at your location 1-5 days after you summon him, depending on his distance from you at the time you summoned him. When he arrives, you may choose one item from him without trading another object in return, and the trade is treated as though you traded an item worth high sentimentality.

Source: The Gray Merchant of Asphodel