Great Vaults of Miryr

The great vaults of Miryr were created long ago by a powerful ancient deity. The vaults exist outside of the material plane, yet are closely connected to it. Each vault is attached to a section of the material plane equal in size to a medium continent. All treasure created and all coins minted on these areas in the material plane will have a duplicate appear in one of the vaults. As such, the vaults overflow with riches of many kinds. Though they are of finite size, they expand as more wealth is accumulated in their halls.
Although it is difficult for mortals and deities alike to enter these vaults, it is possible to gain access to them using a Construct of Miryr. Throughout history, a handful of creatures have managed to access the vaults using these constructs. Though those who come to the vaults to gain riches fall for their greatest defense. Whenever attempting the collect any of the treasure that is stored in a vault, the creature doing so will fall under the curse of the vault. Those inflicted by this curse become a servant of the vault, being forever bound to remove and add to the vault. These unfortunate souls will spend the rest of their lives with an overwhelming desire to give away the treasures of the vault through trade. They do, however, feel obligated to receive a fair amount of gold when selling these items, wanting to add this gold back to the vault.
These servants of the vault will erect shops within the borders of the area connected to the vault. The shape of these shops differs greatly depending on which vault a cursed creature stole the treasure from. Some vaults urge their servants to build prestigious and glorious shops that attract many customers, while other vaults cause the construction of secretive and consecutive shops. One thing that these shops do have in common is that they contain a gateway to the matching vault. These gateways can only be opened by a servant of the vault.
Deep within the vault lies the Treasure Hall of the Golden Mimics. This is a special place, where those who visit can face a challenge to obtain a gift from the vault. The gift is an item selected by the vault matching the individual who accepts the challenge. This place allows the party to obtain their individual magic items in case they missed them. Once they missed one of these items, the construct of Miryr they carry will alert them that a new challenge awaits them in the treasure hall. The plays may face this challenge together and obtain the missed item. The challenge is always a golden version of a boss of their choice that they previously defeated. This version of the boss is scaled up to match their level and can be any notable enemy they faced and defeated so far (excluding The Great Zhars).