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 sixteen +1/+1 counters on a creature you control with power 3 or greater.
At the beginning of your next upkeep, Mayael's Aria triggers, causing you to put a +1/+1 counter on each creature you control, gain 10 life and win the game.
This ingenious loop transforms a single mechanical kill spell into an overwhelming cascade of explosive growth. By targeting Verdurous Gearhulk with Saw in Half, you set off a compounding chain reaction where Anointed Procession doubles the resulting token copies, flooding the battlefield with four massive mechanical titans. Each of those newly spawned tokens triggers its own entry ability, distributing a massive combined total of sixteen +1/+1 counters onto your creatures. With your board's power scaling astronomically, Mayael's Aria easily scales through its upkeep triggers—pumping your team, netting you 10 life, and ultimately scaling a creature past power 20 to secure an instant victory.