Trash the Town
The green combat trick has always been a compromise: you buy one effect and hope it lines up with the board, and if the game shifts you are stuck holding a card that only does one thing. Spree collapses that guesswork by letting a single one-mana instant scale to the exact moment. Pay two for a pair of +1/+1 counters when you need a body to survive or push through; add trample when a chump blocker is the only thing in the way; bolt on the two-card draw rider when an unblocked attacker can turn combat into a windfall. The base cost stays trivial, so the card is never dead in hand: the additional costs are what tune it from a minor pump into a game-swinging refuel. What makes this more than a stack of modes is the timing. Held to instant speed, it rewrites a combat step after blocks are declared, letting the counters stick permanently while trample and the draw trigger evaporate at end of turn. That split between what persists and what expires is the design's spine: the counters are the investment, the temporary riders are the ambush. Green rarely gets to draw cards off combat, and stapling that onto the same flexible frame that pumps and grants evasion means one card can decide how a race resolves without committing to which lever it pulls until the moment it matters.
