Symmetry Matrix

The trigger keys off a condition almost no aggressive deck naturally meets: a creature whose power exactly equals its toughness. That single clause rules out the lopsided 3/1s and 4/2s that fast red-white shells lean on, and rewards instead the squares (1/1 tokens, 2/2 golems, the fat balanced constructs) that a certain kind of artifact deck already fields. The optional is the honest part of the exchange. Each qualifying arrival is a decision, not a gift: you weigh a card against whatever else that mana could deploy, so the engine only turns profitable once the whole shell is pointed at matched-stat bodies and you have mana to spare. Where the design reaches furthest is the word "enters." Because it fires on entering the battlefield rather than on casting, it catches token generation, reanimation, blink loops, and copy effects that a cast trigger would miss entirely: however the square-statted body got onto the field, it pays out. The four-mana rate with no body of its own confirms what kind of card this is. It contributes nothing to a board on its own and asks you to have already committed to a deck full of matched creatures before it earns a slot, which is exactly the demand a symmetry payoff should make: an engine whose per-trigger cost is small but whose inclusion cost is a whole deckbuilding thesis.