Just trust me on this one: save yourself some space, buy the appropriate protection, and just invest in booster boxes
They represent a Pokmon that has been trained to the highest levels possible, giving it powerful attacks and new abilities, along with more HP and a diferent Retreat Cost
For my two-color decks, its simple: mixing the two halves gives an easily identifiable color-paired box
However, Mew ex is different from regular Mew, with different attacks, HP, and rarities, which is true for all EX versions as well
By today's standards it might seem a little slow and clunky, but it's a card drawing machine
Then, when news broke that the expansion only had a very small print order, the popular find turned into a full-on urban legend