Rift is a rare Legendary Land card from Mystery Booster Playtest Cards 2019 (CMB1), collector number 119. Current market price: $1.50, TCGplayer market prices via Scryfall.
Before drawing your hand, you may start the game with Rift in your opening hand. If you do, draw one fewer card. (Mulligans continue as normal.) Rift enters tapped. {T}: Add {C}.