Winds of Qal Sisma

A Fog with a clause that pays the defender for fielding a real threat. A plain Fog is symmetric: it stops both sides' combat damage, buying a turn but doing nothing to advance the defender's own clock. The ferocious upgrade rewrites the math. With a creature of power 4 or greater in play, the prevention narrows to only the damage dealt by creatures your opponents control, which means your own blockers still deal theirs. So when the opponent commits to an alpha strike, you throw your board in front of it: your creatures take no damage and connect for full, killing attackers for free while your opponent's board comes back diminished. That asymmetry is the whole design. Green, the color that builds the biggest bodies, gets a defensive trick that punishes the opponent for attacking into a board that was already winning the long game. The 4-power condition is the price for the one-sided mode, and it lines up cleanly with the deck most likely to want the effect: the one already deploying a fat threat. The base mode keeps it functional when nothing qualifies, still a Fog, just without the teeth. It sits among the conditional fogs built to solve the effect's oldest problem, that buying time is not the same as winning, by letting the time you buy double as a combat blowout that thins the other side of the table.