Primal Might

Green's fight spells trade removal quality for removal quantity: they need a body already in play and a favorable power comparison, which is exactly the friction this design pays down. The pump comes first and the fight resolves after, so the +X/+X does double duty: it decides the fight and, because the boost lasts through the turn, it carries into a subsequent attack if the creature survives the exchange. The math is what makes the X worth paying. Sink X into a decently sized attacker and you both clear the opposing blocker and leave behind a threat grown past whatever else the defender is holding. The "up to one target creature" wording is the load-bearing detail: because you don't need an enemy creature to resolve the spell, a green deck holding this is never stuck with a dead card against an empty board, spending X on a straight pump ahead of the attack step instead. Where an unconditional removal spell answers a creature and stops, this scales your creature into a threat and answers theirs in the same cast, at the cost of committing a body to the exchange and needing the power to win it. It descends from a long tradition of green "make my creature big, then point it at yours" effects, and the sorcery timing is the tax the flexibility pays: the X ceiling rises with your mana rather than capping at a fixed number, but every use has to happen on your own turn, during a main phase, with the board read locked in.