Cast Saw in Half by paying 2, destroying Verdurous Gearhulk and creating four token copies of it with base power equal to half the destroyed creature's power and base toughness equal to half the destroyed creature's toughness, rounding up each time.
When the Verdurous Gearhulk tokens enter the battlefield, they trigger, putting at least nine +1/+1 counters on Nested Shambler, and the remaining seven +1/+1 counters on any creature(s) you control.
Kill Nested Shambler, triggering its ability, creating at least twenty 1/1 Squirrel creature tokens.
At the beginning of your next upkeep, Epic Struggle triggers, causing you to win the game.
This intricate assembly scales your creature count exponentially by using Saw in Half to slice Verdurous Gearhulk into four miniature token copies, flooding the board with massive entering-the-battlefield triggers. Those distributed +1/+1 counters pump Nested Shambler into a towering threat, so that when it finally perishes, its death trigger creates an overwhelming horde of Squirrel tokens. This entire token-generation strategy is turbo-charged by Anointed Procession, which doubles every token created along the way to ensure you comfortably cross the twenty-creature threshold required by Epic Struggle to instantly claim victory on your next upkeep.