Smell Fear

Fight spells almost always sell themselves on the removal: point your creature at theirs, trade the extra power for a dead blocker. This one buries that clause under proliferate, and the ordering matters. Proliferate resolves first, so any +1/+1 counters already sitting on your creature grow before the fight is assigned, which turns a marginal trade into a favorable one and lets a counters deck pump its fighter without a separate combat trick. The reach extends past the board, too: proliferate hits loyalty, poison, and every other counter you control, so the fight is genuinely the secondary mode on turns where you have a planeswalker to tick up or an infect clock to advance. Read the two halves separately and they pull opposite directions. A pure fight spell wants a big creature and an enemy creature to kill; a pure proliferate spell wants a board full of counters and does not care about combat at all. Stapling them together makes a card that is rarely fully dead, because the "up to one" clause lets the fight fizzle harmlessly into an empty enemy board while the proliferate still lands, so long as you control a creature to name as your fighter. It is a green counters-matters engine piece that happens to remove a creature, rather than a removal spell that happens to proliferate, and reading it the other way around tends to disappoint.