Steady Progress

Proliferate's debut as a standalone effect, and the cleanest possible argument for why the mechanic belongs in blue. The whole keyword is a counter-amplifier with no counters of its own, so a deck that runs it needs a board state worth amplifying: charge counters on artifacts, +1/+1 counters on creatures, loyalty on planeswalkers, poison on an opponent. The design problem is that an effect this conditional risks doing nothing in a vacuum, and the answer here is the most blue solution available: bolt a cantrip onto it. Drawing a card means the spell is never dead, even when there is nothing to proliferate, which lowers the deckbuilding cost of including it and turns the body of the card into a free roll rather than a gamble. That structure (a synergy payoff stapled to a card-neutral floor) is what separates the proliferate cards that earn a slot from the ones that read as build-around traps. Cast at instant speed, it also rewards patience: hold it until a poison counter, a planeswalker activation, and an end-of-turn combat all want a second tick at once, then refill your hand in the same breath. It is the modest, no-frills version of the mechanic, a single instant with nothing to recur or rebuy, asking nothing of your deck except that you have already done something worth doubling down on.