Ilysian Caryatid

Green's mana dorks have always tapped for color, and plenty tap for any of the five: Birds of Paradise, Sylvan Caryatid, and Paradise Druid all fix a manabase for a single body. This one keeps that fixing floor and adds a scaling clause, and that clause is why the card behaves so differently from its cousins. On an empty board it is an ordinary two-mana accelerant, producing one mana of any color. The moment you control a creature with power 4 or greater, the same tap yields two, and that threshold is the design's real argument: the doubling responds to board state, not to how many turns have passed. So the dork stops competing with your fatties for mana and starts feeding off them. A Steel Leaf Champion or any suitably large threat flips it from color-fixer to genuine ramp piece, so the payoff arrives right as your curve peaks and you already have big bodies to accelerate into. The tension is intentional: you want the extra mana early, but the condition asks you to have already committed a threat to earn it. It never hands you power ahead of your board; the acceleration is a reward for a green board state you were building toward anyway, not a shortcut to one.