Although many different cards could have Ditto underneath them, the most valuable of them all is the Bidoof
-Can be activated at almost any time (not being able to be activated during the damage step is an exception) -Negates ANY activated effect, not just targeting 1 card on field, or that would destroy a card
Proxies are great for test decks, commander decks and protecting valuable originals and expensive staples
Both players take damage equal to half the combined ATK of every destroyed monster, which will usually add up into the thousands
Our other win condition here involves Trade Routes, one of the best cards in the deck
This is different from something being banned as a commander, where suddenly someone's entire deck is invalid