Simic Ascendancy by paying ({1} magic symbol) ({G} magic symbol) ({U} magic symbol) , putting three +1/+1 counters on
Crystalline Crawler.
Simic Ascendancy's first ability triggers, putting four growth counters on it.
Activate
Crystalline Crawler's first ability three times by removing three +1/+1 counters from it, adding ({1} magic symbol) ({G} magic symbol) ({U} magic symbol) .
Repeat until
Simic Ascendancy has twenty or more growth counters.
At the beginning of your next upkeep,
Simic Ascendancy triggers, causing you to win the game.
Results
Win the game at the beginning of your next upkeep.