Judgment of Alexander

A Fog that answers back, but only for a deck that has committed to commander-sized creatures. The prevention shell is old white technology, the kind that has been shrugging off alpha strikes since the earliest sets, and on its own the card is exactly that: an instant that walls off a lethal swing for a turn. The teeth live in what the prevented creature damage triggers. When damage from any creature is prevented (combat or otherwise: an attacker, a pinger, a source that would burn you through combat), each commander creature you control deals a single burst of damage equal to its power to that creature. This is not a point-for-point redirect of the damage prevented but a fresh hit sized entirely by your general's stats. A one-damage source and a twelve-damage source both eat the same retaliation, which means the punishment scales off the size of your commanders rather than the size of the assault. That reframes the whole spell. The instant resolves first to set up the shield; the retaliation triggers only when damage is actually prevented, which for a full swing means the volley lands during the combat damage step, after blocks, catching a wide board and answering it with fire the attacker never accounted for. The floor is a plain prevention effect that still blanks all your opponents' damage but retaliates nothing when you control no commander creature or against noncreature sources like burn; the ceiling is a one-sided sweeper that ends a race the moment your opponents overextend into it.