Simic Ascendancy + Conclave Sledge-Captain

Prerequisites

You control a creature with power 3 or greater that can attack this turn and that cannot be blocked an opponent.

Steps

1. Cast Conclave Sledge-Captain by paying {5}{G}.
2. When Conclave Sledge-Captain enters the battlefield, its backup ability triggers three times.
3. Resolve the first trigger, putting a +1/+1 counter on the creature with power 3 or greater, and causing it to gain the printed abilities until end of turn.
4. Simic Ascendancy's first ability triggers, putting a growth counter on it.
5. Repeat from step 3 for each remaining trigger.
6. Deal combat damage with the creature that was targeted in step 3, triggering the creature's ability three times.
7. Resolve the first trigger, putting a number of +1/+1 counters on the creature equal to the damage dealt.
8. Simic Ascendancy's first ability triggers, putting that many growth counters on it.
9. Repeat from step 7 for each remaining trigger.
10. At the beginning of your next upkeep, Simic Ascendancy's second ability triggers, causing you to win the game.