Growing Ranks

Populate rewards you for already having tokens, which is why the mechanic always lived or died on the engine it was stapled to. Most printings attached it to a one-shot spell or a creature with a triggered ability. This is the version that never stops: a free, untargeted populate at the start of every one of your upkeeps, with no cost beyond the four mana to deploy it and the requirement that you control a creature token worth copying. That last clause is the whole balancing act. The enchantment does nothing on an empty board; it asks you to bring your own token and then hands you one more, every turn, until someone deals with it. Copy a 4/4 angel and you add another the following turn, and another after that: linear, but relentless, and never costing you a card. The detail that decides which token to copy is that populate duplicates only the base creature, not the +1/+1 counters or anthem effects layered on top, so the right target is the token whose printed characteristics are worth duplicating rather than the one your lords have inflated. It is a slow engine by design, advancing only on your upkeep and only as fast as your existing tokens are good, but in a board flooded with bodies it turns a single strong token into a problem that compounds one creature at a time, which is a problem best answered at the source.