Lingering Souls is a uncommon Sorcery card from Duel Decks: Sorin vs. Tibalt (DDK), collector number 24. Current market price: $0.18, TCGplayer market prices via Scryfall.
Create two 1/1 white Spirit creature tokens with flying. Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)