Wondrous Item, legendary
The Bag of Holding Everything is a pretty normal bag of holding, except it has over a 100 thousand bags of holding within it, each with a spell scroll that can do an extremely specific effect, since you can't logically draw any item the same time twice or even get what your intending the user rolls a d20 to decide how effective the effect of the scroll drawn is to the situation, the specific effect will be made up by the dm on the fly depending on the roll