Pulverize

Read at its printed cost, this is a sluggish artifact wrath: six mana for a sorcery that flattens every artifact on the board, your own mana rocks included, with no upside to justify the rate. Nobody pays the printed cost. The whole card lives in its alternative payment, which lets a mono-red deck spend two Mountains in place of mana and erase an entire artifact-based plan with one card at the moment an opponent has overcommitted to it. That trade is the design's hinge. You are paying in permanent resources rather than mana, so the question becomes whether the artifacts dying are worth more than two of your lands and the tempo wobble of shrinking your own mana base. It sacrifices Mountains, not basic Mountains, so any land carrying the Mountain type (dual lands, shocks, a Mountain-typed nonbasic) is valid ammunition, quietly widening what can feed it. The board-wide reach cuts both ways, killing your artifacts alongside theirs, which punishes a deck running its own mana rocks or artifact lands and rewards one that wants almost none. Its kin are the other pitch-cost effects that let a color trade away land to dodge color-screw and heavy mana commitment, sweepers that function as deckbuilding levers rather than spells you sequence turn to turn. Build few artifacts and many Mountains, and those Mountains become a free button to press when the table tips artifact-heavy.