Everlasting Torment

Three rules-text statements, each one a hammer aimed at a different defensive crutch, stacked into a single static enchantment. Lifegain is the most common way fair decks blunt aggression, so the first line removes it for everyone. Damage prevention (fog effects, protective shields, the Circle of Protection lineage) is the second-most-common, so the second line nullifies it across the board. The third line is the strange one: it doesn't just enable wither, it forces every source's damage to creatures to deliver as -1/-1 counters, including burn spells, combat between vanilla creatures, and even your opponents' attacks. That last clause rewrites how a board state ages. Creatures that trade in combat don't bounce back next turn; they shrink permanently, and a board full of small bodies erodes toward zero. Either a black or a red shell can field it on its colored pip, fitting a card whose three effects each lean on a different color's grudge: black's contempt for lifegain, red's hatred of prevention, and the -1/-1 attrition that both colors flirt with. It is an unusual kind of symmetry-breaker, because the symmetry is the point. Everyone loses access to the same safety nets at once, and the deck built to weaponize wither and unblunted damage comes out ahead by construction rather than by exception.