In fact, even deciding what deck to play can be tricky, perhaps you want to base it around your favourite Pokmon or you have a specific goal in mind of how you want the deck to work
Vintage tournaments are unsanctioned and allow growing numbers of proxies (usually five to ten, sometimes unlimited)
Nested Shambler might only make one Green Squirrel creature token when it dies, but if I were to play Yavimaya, Cradle of Growth to make all my lands Forests and enchant that Zombie with Blanchwood Armor to give it +1/+1 for each Forest I control, I could be looking at an awful lot of Squirrels
The Three Brothers not only gives you one deck but multiple dual-color Leaders (Black/Yellow Luffy, Red/Yellow Sabo, and Blue/Yellow Ace) letting you experiment with different strategies using the same card pool
Know a friend whod like this
You can only sell cards if you have 3 or more of them