Thwart the Enemy

Fog has always been green's, and the interesting move here is one-directional: instead of blanketing the turn in both directions the way the original does, this shield falls only on creatures your opponents control. Your own attackers still connect. That asymmetry turns a pure defensive stall into a two-way play. Cast it before your alpha strike resolves and you swing for everything while your opponents' blockers deal nothing back; hold it as a straight combat wall on a turn you have no board of your own. The instant-speed window is the whole leverage point, letting it sit in hand as an ambush that punishes an all-in attack after blocks are declared. It reads as a defensive card and functions as a tempo swing, which is exactly the tension green's premium Fog variants keep circling: the color pays up (three mana against the one-mana baseline of the archetypal Fog) for a beater-friendly clause instead of a symmetrical one. The trade is fewer copies of a strictly cheaper wall in exchange for a spell that can be part of an offensive line rather than just a stay of execution.