Fanatic of Rhonas

The trick with any explosive mana dork is the cost of unlocking it, and this one asks for a board state rather than a wait. The base tap for a single green is the floor; the ferocious clause quadruples output the moment you control something with power four or greater, turning a defensive 1/4 into a ritual that produces four green on its own the turn it comes online. That gate is the balancing act: the card wants to sit behind a big threat, not accelerate toward one, which means it slots into decks that already resolve heavy hitters rather than the ramp shells that would abuse a Priest of Titania or a Llanowar Elves start. The 1/4 body matters here too, because it survives the incidental sweeps and pings that clear a one-drop dork, so the mana is still there on turn four when the ferocious condition finally goes live. Eternalize is the second life the card rarely needs but occasionally wants: a 4/4 Zombie token from the graveyard that clears its own power-four threshold, so the recurred copy taps for four green with no other creature in play. The design folds the enabler and the payoff into one card, and the fixed exiling nature of eternalize keeps that from being a repeatable engine.