There is an argument to be made that the MTG community is highly aware of the appearance of MTG cards, unusually so in the world of trademarks, and that they would be able to recognize altered cards because of their sophistication
So, when you build a reasonable collection of pocket monsters (it won't take you long, considering the number of free cards the game throws at you in the first hours of gameplay), you can take them into battle
You can either build around a legendary creature and try to find cards that will complement this creatures abilities (referred as top-down building) or you can build around a mechanic/theme or combination of both that you find interesting and search for a Commander that will best fit to lead the deck (referred as bottom-up building)
It does not matter when this occurs, just that it occurs
By swapping its text box with another creature, it can steal powerful abilities and shut down opposing commanders, which creates chaotic board states and forces opponents to rethink their entire game plan
Stores have to make a profit off the cards theyre buying and lower conditions of cards will lower the value of the card