Gilder Bairn, Biomancer's Familiar, and Utopia Vow

Prerequisites

• Gilder Bairn on the battlefield
• Biomancer's Familiar on the battlefield
• Utopia Vow on the battlefield

Steps

1. Activate Gilder Bairn's ability from Utopia Vow 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