Gemini Engine

Doubling damage output the moment it swings, but only for the duration of one combat: that is the bargain this Construct strikes. The Twin token copies the parent's current power and toughness, attacks alongside it, and is gone before end-of-turn triggers can be banked. That sacrifice-at-end-of-combat clause is the whole reason it is not a permanent army-doubler; you cannot hold the token back to chump-block on the crackback, and any pump spell pointed at the engine is read by the Twin only at the instant of creation. The real design hook is the live power-and-toughness copy. Boost the engine before the attack trigger resolves and the Twin enters bigger; equip it, hang +X/+X on it, and the token mirrors the inflated line, so the card wants to anchor a beef-and-swing plan rather than carry a board by itself. A 3/4 body for six is deliberately unimpressive on its own; the math only justifies the cost once you are stacking modifications onto it and watching them double across the attack step. It belongs to that strain of artifact creatures whose printed stats undersell their ceiling, where the entire value proposition is what happens after you start feeding it.