Banned Eldraine Card is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

As an additional cost to play Banned Eldraine Card, pay , , , , , or . It becomes a copy respectively of Cauldron Familiar, Escape to the Wilds, Fires of Invention, Lucky Clover, Mystic Sanctuary, Once Upon A Time for the rest of the game in all zones. (You can't choose Oko. Because let's be real, nobody wants to play against Oko again.)