Gilder Bairn, Agatha's Soul Cauldron, and Gyre Sage

Prerequisites

• Gilder Bairn in exile
• Agatha's Soul Cauldron on the battlefield
• Gyre Sage on the battlefield

Steps

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

Results

• Infinite green mana
• Infinite proliferate