Infinite Mana Piece

Cards that form the engine of an infinite-mana loop, either by untapping a mana rock that produces more than its untap cost, untapping all nonland permanents while a free spell recurs, or copying activated abilities to double mana output. Basalt Monolith pays to untap itself, Dramatic Reversal untaps every nonland permanent, Rings of Brighthearth copies activated abilities, and Isochron Scepter loops a stored instant. Distinct from Damage Win, which empties life totals with mass burn and drain, this set covers the mana-generating piece that fuels those payoffs rather than the payoff itself.