Shrivel

For a symmetrical sweeper, the size of the number decides everything, and -1/-1 to everything is the smallest cut that still kills anything. Where Pyroclasm trades two mana for a clean three-damage wipe and Drown in Sorrow throws in scry, this clears only the genuinely small: tokens, mana dorks, one-toughness aggressive starts, the chaff that floods a board before the midgame. Anything with two toughness shrugs it off entirely. That makes it a precise instrument rather than a board reset, and the precision cuts both ways: it asks the caster to be the side without the small creatures, or to be willing to lose them too. The -X/-X structure also does work a damage-based sweep cannot, killing every one-toughness creature regardless of its power, ignoring indestructibility and damage prevention, and shrinking the survivors by the same step. Because the shrink applies to your board too, it is not a tool for winning combat math: a sorcery cannot be held for the opponent's attack, and even when both sides lose a point of toughness, no blocker is suddenly favored that was not already. Being a sorcery is the real constraint here; there is no end-of-turn ambush, no reactive line, only a preemptive sweep on your main phase against creatures already on the table. The ceiling is low by design, but the floor is a two-mana answer to go-wide starts that asks nothing of your own board if you built around it.