Hunter's Ambush

Fog with a partisan streak. The standard version prevents all combat damage flat, a colorless effect in a green frame that any defensive deck can run as a blank pane of glass. This one rewrites the clause to spare your green creatures, turning a pure stall into a one-sided wall: your green attackers connect while everyone else's swing fizzles. That asymmetry is the design conceit, and it is also the catch. The value scales with how green the board is, which means the card peaks precisely when you need it least (you are ahead, your green creatures are already winning combat) and outright stops functioning as a Fog the moment the threat coming at you is green too: prevention that ignores green attackers does nothing against green attackers, so the mono-green mirror is the embarrassing edge case the wording invites. It sits in a long line of color-conditional combat tricks that trade reliability for a sliver of in-color upside, cards that read cleaner than they play. As a defensive turn-buyer against a typical multicolor or off-color board it does the job a Fog does; as a tempo swing it asks the board to cooperate in a way combat rarely does, and against the one matchup where a green deck might want extra reach, it is dead.