However, Commander is a singleton format, meaning you can only put one of each card in your deck
Its not impossible to deal with, but even one hit with this thing is going to change the rest of the game
Finally, since players ran it with four Rainbow Energy (Aquapolis, 144/147) to get past the limitation of four copies of the Darkness Special Energy, it could fit in just about any deck using any Energy type
Decks with cards like The Rack and Ensnaring Bridge are always on the edge of playability, and black-based decks in EDH have plenty of ways to punish people by making them discard
And just like any other card game, certain cards, especially those with print errors, become worth boat loads
It can define what a card is used for - as it does in the case of Trainer, Energy, and Pokmon cards - or it might explain what kind of Energy a particular Pokmon relies on