Faeburrow Elder, and Umbral Mantle

Prerequisites

• Faeburrow Elder on the battlefield
• Umbral Mantle on the battlefield
• Umbral Mantle attached to Faeburrow Elder
• Faeburrow Elder does not have summoning sickness
• There are at least four colors among permanents you control

Steps

1. Activate Faeburrow Elder by tapping it, adding at least
2. Activate Faeburrow Elder by paying and untapping it, giving itself +2/+2 until end of turn
3. Repeat

Results

• Infinitely large Faeburrow Elder until end of turn
• Infinite mana of colors among permanents you control