Overgrown Battlement, and Umbral Mantle

Prerequisites

• Overgrown Battlement on the battlefield
• Umbral Mantle on the battlefield
• Umbral Mantle attached to Overgrown Battlement
• You control at least three creatures with defender
• Overgrown Battlement does not have summoning sickness

Steps

1. Activate Overgrown Battlement by tapping it, adding at least
2. Activate Overgrown Battlement by paying and untapping it, giving it +2/+2 until end of turn
3. Repeat
4. If you control four or more creatures with defender, this combo nets infinite green mana

Results

• Infinitely large Overgrown Battlements until end of turn
• Infinite green mana