Better Than One is a rare Sorcery card from Unstable (UST), collector number 128. Current market price: $0.22 (foil $0.87), 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.)