Flowstone Slide

The genius is in the symmetry that isn't. +X/-X reads neutral on paper: both halves of the board grow and shrink in lockstep. But toughness is the dimension that kills, and the modification scales by the same X on both axes, so the spell becomes a one-sided sweeper for whoever fields the larger creatures. Set X to wipe the opponent's two- and three-toughness board, and your own four- and five-drops survive with bloated power; pick the number that clears their team while leaving your largest creature standing, and the same cast that kills their side pumps yours toward lethal. Casting it well means reading the toughness curve on both halves of the table and finding the value where their creatures die and yours don't, which turns the spell into a calculation puzzle rather than a button. The conditional symmetry is what keeps it honest: the spell is only as lopsided as the board state lets it be, and a flooded mirror of equal toughnesses collapses it into a wash. This is a red tradition of pricing asymmetry into a symmetric template, trusting the caster to engineer the disparity rather than handing it over for free. Restricting it to sorcery speed seals the rest: there is no combat ambush here, and the swing has to land on your own turn, where the math is yours to control but the surprise is gone.