Mirror Entity

The X is the kill switch. A 1/1 that does nothing on an empty board, this becomes a one-card finisher the moment a few bodies are in play: pay the rest of your mana, and every creature you control turns into an identically sized beater that also shares every creature type. The scaling is the whole tension. There is no cap and no commitment until you choose to fire it, so the activation reads as a delayed alpha strike priced exactly at the mana left after deploying threats. Because it sets base power and toughness rather than granting a bonus, it overwrites anvil-sized stats and dork-sized ones alike, comfortable on a flood of tokens or a board of mana creatures. The tribal rider is not incidental: granting all creature types turns a swing into a payoff for every lord, every "creatures you control of type" effect, every changeling synergy on the board, and the card itself is already every type thanks to its changeling line. That doubling, a tribal anthem stapled to a finisher, is rare enough that go-wide white decks kept finding room for it long after most three-drop creatures aged out. It asks one question of the deck around it: enough bodies, enough open mana to make the X lethal? When the answer is yes, the 1/1 stat line stops mattering entirely.