Battlegate Mimic

Idle, this Shapeshifter is a 2/1 that loses combat to almost everything; trigger it and the math inverts, swinging to a 4/2 with first strike that eats a 3/3 and walks away clean. The catch is what counts as a trigger: not a red card, not a white card, but a spell carrying both colors on the same card, which means the gold and hybrid cards living at the intersection of red and white. That single restriction is the whole design. A buff this aggressive would be reckless on a generic "cast a red spell" clause, so the payoff is gated behind a deck genuinely committed to two colors rather than one with a splash. First strike does more work than the raw power here: a 2/1 attacker is a chump in the early turns, but a 4/2 first striker is a credible clock that trades up against larger blockers without dying to them, and it costs nothing extra beyond a multicolor spell you wanted to cast anyway. The turns it triggers, it is a real threat; the turns it does not, it is fragile filler. That gap is the deckbuilding puzzle the card hands you: not whether you play red-white, but how many of your spells honestly wear both colors before combat resolves.