Gilder Bairn, Agatha of the Vile Cauldron, and Song of Freyalise

Prerequisites

• Gilder Bairn on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• Song of Freyalise on the battlefield

Steps

1. Activate Gilder Bairn's ability from Song of Freyalise by tapping it, adding
2. Activate Gilder Bairn by paying and untapping it, doubling each counter on target permanent
3. Repeat

Results

• Infinite proliferate for permanents