Pitiless Carnage is a rare Sorcery card from Outlaws of Thunder Junction (OTJ), collector number 326. Current market price: $0.74 (foil $0.98), TCGplayer market prices via Scryfall.
Sacrifice any number of permanents you control, then draw that many cards. Plot {1}{B}{B} (You may pay {1}{B}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)