Sphere of Law
Color hosers come in two grades, and this is the surgical one. Where a blanket damage-preventer covers every source, this enchantment narrows its gaze to a single color and pays you back with continuous, automatic mitigation rather than a single emergency fog. The two-damage reduction is calibrated against red's signature output: it shaves a small burn spell toward irrelevance and turns most attacking creatures into chip damage, all without you spending a card or a mana once it resolves. The crucial detail is that the reduction is per-source and per-event, not per-turn: every red creature that connects, every burn spell on the stack, every ping from a tapper has two of its damage stripped independently. Against a wide red board or a turn full of burn, the prevention applies to each instance at once. That breadth is precisely what the design pays for by going mono-color. A permanent static prevention this strong against one color would be oppressive against all five, so the wager is total commitment to a single color of source: it does nothing whatsoever against the other four. The lineage runs through every targeted hoser back to the earliest circles of protection, all built on the same bet: that the matchup is read correctly enough to justify dedicating a card to beating exactly one thing. When the read is right, red's entire clock quietly evaporates; when it is wrong, the battlefield carries a blank.
