Code of Constraint

Held for the combat step, this is a soft Fog against one attacker with a cantrip stapled on: -4/-0 blunts the incoming damage, you replace the card, and you move on with your hand intact. The Addendum clause rewrites what the spell is entirely. Fire it before combat during your first main and it stops being a defensive shrug: now the creature taps and stays frozen through its controller's next untap step, which is functionally a two-turn tempo lock on a permanent you never had to answer. That is the tension the design resolves. Instants beg to be held for the reactive window; Addendum pays you for spending early, and the payoff here is large enough that breaking the instant-speed habit is usually the correct line. The -4/-0 rather than a symmetric shrink is the detail that keeps the card in its lane: it neutralizes an attacker without ever killing anything, so the whole thing reads as tempo plus card advantage rather than removal. Blue does not get to spend three mana and cleanly kill a creature, but it does get to buy time, tap something down, and keep drawing. This is that trade priced precisely, with a keyword that turns the reward knob based on whether you had the discipline to commit before the fight.