Felling Blow

The trick here is that the counter and the fight are sequenced, not simultaneous: the +1/+1 counter lands first, then the pumped creature deals damage equal to its new power. That ordering is the whole point. Green's fight effects have historically forced a two-way exchange, your creature and theirs trading blows, which meant your attacker took damage back and could die to a smaller blocker. This does not fight at all. It bites: one-directional damage, dealt at the creature's boosted power, with nothing coming back. The counter buys the removal a permanent upgrade on top of the kill, so the card is doing two jobs on the same turn (growing a threat, clearing a blocker) without asking your creature to survive a counterattack the way a true fight spell would. The cost of that clean profile is the setup requirement: it needs a creature you control already on the board with enough power that its size-plus-one clears whatever you are aiming at, and it is locked to sorcery speed, so it cannot ambush an attacker mid-combat or answer a flash threat. Within those limits it reads as green's answer to the old problem with fight removal, the reciprocal damage, solved not by adding lifegain or indestructibility but by simply pointing the damage one way.