Pokemon World Championship Master Key Release date : 2010 Highest value of the card at auction: $26,900 Grade : BGS 9 Only 36 Master Key trophy cards were made for the 2010 Pokemon World Championship and one of those cards somehow made it to an auction
P (Parallel): An alternate version where the character composition and background differ from the normal version
Destroy up to one target artifact, up to one target creature, and up to one target enchantment
Adding 20 cards to your deck seems like a massive drawback that would hamper the consistency of your deck yet Yorion got the ban hammer in several formats, and some Modern decks still tinker with 80 cards, even without the extra creature in their sideboard
There are certainly cards that work fine with both and it can be done but you will either have stuff that does nothing with one half of your engines or you will have a pretty underwhelming Sneak Attack compared to what it can do
Listening to his thoughtful answers, I start to have a new appreciation for the game