Conclave's Blessing

The buff scales with everything except the creature it enchants: each other creature you control adds +0/+2, so the aura does nothing on a barren board and turns absurd once the board is wide. Convoke is what makes that math pay off in both directions. The same creatures that inflate the toughness bonus are the ones that can fund the spell, including its white pip, since a tapped creature covers one mana of its own color. The wider the board, the bigger the bonus and the cheaper the cast: a swarm deck can tap a handful of bodies and pay nothing from lands, turning one survivor into a brick wall, while a deck sitting on a lone blocker is left holding a four-mana enchantment that barely moves the needle. There is no power granted at all, which fixes the card as a purely defensive tool, an answer to mass aggression rather than a way to shove one threat through. The wider design idea here is letting swarm strategies fund high-impact spells with bodies instead of lands, so a deck's cheapest asset (a pile of small creatures) bankrolls its biggest play. This sits at the conservative end of that idea: a wall-maker that stays inert until you are already ahead on the board, then asks those creatures to chip in for the privilege of protecting themselves.