Cast Rite of Replication kicked by paying {7}{U}{U}, creating five token copies of Slurrk.
Put each Slurrk token into your graveyard due to the legend rule.
Each Slurrk token triggers four times, the nontoken Slurrk triggers five times, and Simic Ascendancy's first ability triggers five times.
Resolve all Simic Ascendancy triggers, putting 25 growth counters on it.
Resolve the first Slurrk trigger, putting a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Simic Ascendacy's first ability triggers for each counter placed this way, putting that many growth counters on it.
Repeat from step 5 for each remaining trigger.
At the beginning of your upkeep, Simic Ascendancy's second ability triggers, causing you to win the game.

Win the game at the beginning of your next upkeep

Slurrk, All-Ingesting

Simic Ascendancy

Rite of Replication

On the end step prior to your turn, cast Saw in Half by paying {2}{B}, destroying Slurrk and creating two 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.
Put one Slurrk token into your graveyard due to the legend rule.
Each Slurrk triggers once, and Simic Ascendancy's first ability triggers twice.
Resolve both Simic Ascendancy triggers, putting ten growth counters on it.
Resolve the first Slurrk trigger, putting a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Simic Ascendacy's first ability triggers for each counter placed this way, putting that many growth counters on it.
Repeat from step 5 for the remaining trigger.
At the beginning of your upkeep, Simic Ascendancy's second ability triggers, causing you to win the game.

Combos with "Slurrk, All-Ingesting"