Mnemonic Deluge is a mythic Sorcery card from Commander Legends (CMR), collector number 638. Current market price: $11.02 (foil $15.95), TCGplayer market prices via Scryfall.
Exile target instant or sorcery card from a graveyard. Copy that card three times. You may cast the copies without paying their mana costs. Exile Mnemonic Deluge.