Review a homebrew magic item[5e]

I am planning a campaign for 5e, and I want to introduce a magic item that will help them obtain mundane items and magic consumable items since they will not be able to use a merchant, nor find magic items for the rest of the campaign. Please review it and any comments are welcome. Black Heart Bag: Bag of Create Items

This magic bag consumes demon created black hearts. The bag itself is a red skin bag, with black rope made of hair, with a silver gem in the middle.The immense power that this black hearts posses allow the the bag to create mundane items and magic consumables items. When the bag is feed a black heart the gem will go red indicating that its consuming the heart, depending on the size of the heart, or how much magic it possesses it will take time for it to completely consume it. Once the heart has been consume the gem will go back to silver, with a number in the center. This number indicates how much magic the bag is currently holding.The more magic it has, the more potent the magic item. The maximum capacity of the bag is 4 In order for the bag to increase the maximum magic containment a special magic item must be fed into it.

Magic needed to create items table:

Max Magic Containment Increase Table

Edit: I made tables for the magic items, sorry, I didnt know how to edit so it looks better

Edit 2: Magic Items are selected by percentile on a table based on rarity.