There weren't any individual cards worth anything, unless I wanted to pay to have them graded, but the collector at the flea market was enthused by my father's organization (everything was in binders, in order)
When your commander would go to your hand or library, you may send it to the command zone instead, and it never enters those zones
If you do, all those creatures form a single creature
This line gets more advanced than we're going to deal with for now, but the good news is that for the level you're at right now, in most cases the information you need is right here on the card as you work your way through a game of Magic
Also, know that each link monster will require certain conditions from the cards you use to summon it
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