Only the test of time and countless Magic: The Gathering games will tell if the story that begins with Once Upon a Time will truly have a happy ending. Or the card may end up living a less happily ever after in trade binders of Magic players along with hosts of other promising new cards that never proved themselves worthy of any of the major non-rotating formats.
Once Upon a Time is a green instant, which for 1G lets you look at the top five cards of your library and reveal a creature or land from among those cards to put into your hand. (The remaining cards are afterwards put on the bottom of your library in random order.) The card also comes with the clause that you may cast it without paying its mana cost if it’s the first spell you cast this game. This is, of course, the factor that makes any seasoned Magic player give it, at the very least, a second glance.
Before the release of Throne of Eldraine (October 2019), the Magic community was divided into strong arguments in favor and against the relevance and playability of the card. Some saw it as an obviously broken card, headed for an early ban in Modern and Legacy. Due to the chance of playing it for free, they predicted that the card will be played by, at least, one player in nearly every game of Magic in the future.
Others saw it as an over-cost and over-hyped poorer cousin of Ancient Stirrings and a card of little relevance. At best, it would become a niche card that would only see play in a few lower tier decks. However, there are important differences between Once Upon a Time and Ancient Stirrings:
The last difference may not yet have relevance to any competitively played deck, but each of the others may be deciding factors for players looking to include Once Upon a Time, Ancient Stirrings, or both in their deck.
Besides Once Upon a Time definitely being playable in Standard for its mana fixing ability and to help sculpt your opening hand, it will be interesting to follow how the card will fare in Modern and Legacy as its story unfolds.
Will it really be banned, or will it just be a forgotten tale? The card is predicted to see play in different Legacy decks revolving around Dark Depths, such as Turbo Depths, and in Hogaak, Arisen Necropolis decks. In Modern, it could help put the necessary pieces together in Neoform decks.
Two versions of the card are being printed for Throne of Eldraine: an ordinary version and a borderless version. The price trend for Once Upon a Time being a rare may end up on the high end, especially if it becomes a staple in Standard, Modern, and Legacy. The borderless version could particularly become highly sought-after with a price to match its even higher rarity.