Magma Opus

Eight mana buys you a full turn on a single instant: four damage split anywhere you like, two permanents tapped down, a 4/4 body, and two fresh cards. Stacking four distinct payoffs into one card is only half the work; the other half is answering how you survive to cast something this expensive, and the discard clause is the answer. For two hybrid mana you can pitch the card at any point and bank a Treasure, converting a dead top-decked haymaker into ramp toward whatever comes next. That turns the card's own liability (an eight-mana instant you cannot afford early) into a resource, so the ceiling stays absurd while the floor never bottoms out at "stranded in hand." All-upside finisher on one axis, disposable mana rock on the other: the Treasure mode is the pressure valve that lets the payoff be as expansive as it is. Cast it and you have swung a game outright; discard it and you have simply smoothed a curve. Few spells make their most extravagant effect and their most humble one share the same piece of cardboard, and fewer still make choosing between them feel like no loss at all.