Better Than One is a rare Sorcery card from The List (Unfinity Foil Edition) (ULST), collector number 44. Current market price: — (foil $0.20), TCGplayer market prices via Scryfall.
A person outside the game becomes your teammate. (Choose any number of cards in your hand, on top of your library, or on the battlefield under your control. Those cards become your teammate's hand, library, and permanents, respectively.)