Staunch-Hearted Warrior

Heroic in green is the bluntest version of the mechanic: where the white and blue payoffs turn a targeted spell into evasion, protection, or card advantage, the green ones just get bigger. Two +1/+1 counters per trigger is the heaviest single jump in the cycle, and a 2/2 that becomes a 4/4 the first time you point a pump spell or a protective trick at it skips an entire step on the growth curve. The counters are permanent, which is the quiet part of the math: unlike a temporary buff that vanishes at end of turn, every trigger banks size that survives the turn it was earned, so a creature pumped twice is a 6/6 that stays a 6/6. The catch is the engine has no built-in fuel; this is a body that does nothing extra alone and asks the deck around it to supply targeted spells, ideally ones that do something beyond the counters they generate. That dependency is the whole design tension of heroic: the trigger only fires on spells you cast, so it rewards a low-curve, spell-dense build and punishes the durdle. As the green anchor of that build, it is the most efficient counter-banker in its color band, a creature whose ceiling is determined entirely by how many times you can afford to aim a spell at it.