Mizzix's Mastery is a rare Sorcery card from Outlaws of Thunder Junction Commander (OTC), collector number 175. Current market price: $8.06, TCGplayer market prices via Scryfall.
Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery. Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")