graded pokemon card mystery box Madness Pokémon – United-Collectibles and the possibility of discovering rare and valuable cards MYSTERY BOXES – United-Collectibles

It's a way to nudge story progression forward even when your friends aren't around to join you, while also dialing back any social anxiety that may come from grouping with others you don't know

Pauper Cubes are entirely filled with commons, for example

Card Set(s) -Legacy of the Master- [OP-12] CARD VIEW OP12-102 | SR | CHARACTER Shirahoshi Attribute Wisdom Block Icon 3 Type Merfolk/Fish-Man Island Effect If your Character with a base cost of 6 or less would be removed from the field by your opponent's effect, you may turn 1 card from the top of your Life cards face-up instead

It's great you can use it as removal early, too