Sphere of Safety

Where Ghostly Prison and Propaganda charge a flat two mana per attacker, this prices each swing against a number you control, and you control it by doing the thing an enchantment-heavy deck wants to do anyway: flood the board with permanents that mostly are not the wall itself. Because the static ability counts the Sphere itself, the tax never drops below one per attacker, and it climbs every time another enchantment resolves, turning a defensive piece into a meter that gets steeper the longer the game runs. The deterrent is honest about what it asks for: with one or two enchantments out it is a soft speed bump, easily paid through; the true lockout only arrives once the enchantment count is high, so the card rewards committing to a build that treats enchantments as a resource rather than a splash. That dependency is also its vulnerability, since a single sweeper that clears your enchantments deflates the whole equation at once. The payoff structure is unusually pure for a pillowfort piece: it is not a wall you hide behind so much as a tax that scales with every other card you have already played, growing alongside the strategy instead of standing alone.