pokemon shiny treasure booster box EX - (Japanese) class Pack Shiny Treasure ex (シャイニートレジャーex) set of the Pokemon TCG Japanese Pokemon Shiny Treasures Booster

However in my head they occupy a weird place thats almost feels like filler

A loose short pack has the added risk of being from an opened booster box that has already been checked for no rarity

However, Hydreigon has a way to deal with this

Inti, Seneschal of the Sun lets you access new cards whenever you discard, and both Containment Construct and Conspiracy Theorist simply let you play discarded cards as though they were never discarded

This guy is in my opinion the mac-daddy of cubable un-cards

Now your game state has calcified around this one card, with no real actions or decisions available other than briefly checking if each draw step provides an answer to the lock