Chainer's Edict is a mythic Sorcery card from From the Vault: Twenty (V13), collector number 10. Current market price: — (foil $0.60), TCGplayer market prices via Scryfall.
Target player sacrifices a creature of their choice. Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)