Gilder Bairn, Agatha's Soul Cauldron, and Elvish Archdruid

Prerequisites

• Gilder Bairn in exile
• Agatha's Soul Cauldron on the battlefield
• Elvish Archdruid on the battlefield

Steps

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

Results

• Infinite green mana
• Infinite proliferate