Doubling Season is the poster child for the way in which Commander drives modern Magic card pricing
Sadly, neither of them found any super valuable cards [videos and images of the cards he got here and here]
Level-Up cards must be played onto the corresponding Pokmon like evolution cards (though, in one rule change, it must be the active Pokmon), allowing for a variant of the Pokmon with greater HP, damage and additional attacks - as well as being able to use the moves of the card from which they levelled-up, unlike evolutions
As Wizards once explained online, there is a distinct bluish, violet "pen mark" on the lower part of the card that reads "DECKMASTER," near the end of the word
The philosophy behind the build is just as important as the cards you use on this one
Its a fairly fragile card, especially since the best way to enable the survival ability is by attacking, but it has lots of potential as a repeatable entomb effect