Gilder Bairn, Agatha's Soul Cauldron, and Circle of Dreams Druid

Prerequisites

• Gilder Bairn in exile
• Agatha's Soul Cauldron on the battlefield
• Circle of Dreams Druid on the battlefield

Steps

1. Activate Circle of Dreams Druid by tapping it, adding at least Activate Circle of Dreams Druid using Gilder Bairn's ability by paying and untapping it, doubling the counters on target permanent
2. Repeat

Results

• Infinite green mana
• Infinite proliferate