Stalwart Successor

The trigger here is built to reward doubling, not to double on its own. It watches for the first counter of the turn landing on any creature you control, then adds one more, which means a single external source of counters gets amplified once per creature per turn. The critical wording is "the first time counters have been put on that creature this turn": this is a governor, not an engine. It caps the interaction so that a proliferate loop or a burst of counter-sources cannot cascade into an unbounded pile; each creature banks exactly one bonus counter per turn regardless of how many separate placements it sees. That restraint is what lets the effect read cleanly on a three-mana body without needing a rate penalty elsewhere: it feeds on other cards' counter placement without threatening to run away on its own. Note the boundary the design draws around what qualifies: only cards that literally place counters wake it up (adapt, bolster, outlast, a proliferate spell), while anthem effects and other static buffs, which change the numbers without ever placing a counter, do nothing to it. Black-green has long housed the aggressive, sacrifice-adjacent branch of counters-matter rather than the durdly ramp version, and this sits squarely in that tradition: a menace body that stays relevant as a beater before the synergy assembles, then turns each incidental counter placement into compounding growth while it pressures the board.