Dense Canopy

Most ground-stalling enchantments freeze combat for both armies; this one rewrites a single rule of the air. Flyers, normally the cleanest way to slip damage past a clogged board, can now only block each other, which hands the ground game entirely to the player with more bodies. It is a green answer to a green problem: green has always had the biggest creatures and the fewest evasive ones, so closing off the sky lets a ground swarm punch through unblocked while the opponent's lone evasive threat sits uselessly on defense, able to block only its own kind. The asymmetry is sharper than the symmetric text suggests, because it rewards whoever already wanted to attack on the ground. There is a quieter wrinkle too: a creature with flying can still be assigned to block another flyer, so this does not turn off air combat, it just walls it off from the dirt below. As a piece of color-pie engineering it reads as green staking a claim on grounded aggression, a tax on evasion that costs nothing to maintain and asks only that you have the wider board to exploit it.