Overwhelming Stampede

The Overrun template, scaled to your board's ceiling. The classic mass pump effect handed every creature you control trample and a flat +3/+3; this rewrites the bonus to track the single largest power on your side, so the spell punishes you for going wide with small bodies and pays you for having at least one genuine threat. That self-referential math is the whole design tension: a token swarm of 1/1s nets you a +1/+1 you did not need, while a deck built around even one fatty turns the floor into the kind of damage that ends games on the spot. It scales worst in exactly the decks Overrun was built for and best in decks already winning, which is the inversion that gives it a separate identity rather than a strict upgrade. The trample clause matters as much as the buff: it converts an oversized attacker from a blocked stall into lethal, since the defender now has to eat the full inflated power minus toughness. As a five-mana sorcery, it commits on your main phase with no instant-speed bluff, so the play pattern is the deliberate alpha strike rather than the combat ambush. It is the green finisher in its purest form: develop a board, untap, and read the spell as "win the game" with extra steps.