Leyline of the Void is a rare Enchantment card from Duskmourn: House of Horror (DSK), collector number 106. Current market price: $0.56 (foil $0.86), TCGplayer market prices via Scryfall.
If this card is in your opening hand, you may begin the game with it on the battlefield. If a card would be put into an opponent's graveyard from anywhere, exile it instead.