Dark Chest - deep dark loot item

Watching Docm77 Hermitcraft episodes 18 and 19, with his "null void" "shaddow block" stuff. and it made me think of an possible deep dark loot item- the Dark Chest. The dark chest could be just like a chest that you can open an fill with items (maybe even have it hopper fed), and there would be a way to link that item to an inventory slot- maybe its a second item that you have to hold that are paired items or maybe it opens up another inventory slot. Love the idea, but obviously would need to figure out how to balance it (like you can only have 1 like the ender chest, or it's super rare) The part I like about it is that it would be such an incentive to always go to the deep dark in every world, kind of like how you always go to the end to get shulker shells in every world.