Overgrown Battlement, and Singing Bell Strike

Prerequisites

• Overgrown Battlement on the battlefield
• Singing Bell Strike on the battlefield
• Singing Bell Strike attached to Overgrown Battlement
• You control at least seven creatures with defender
• Overgrown Battlement does not have summoning sickness

Steps

1. Activate Overgrown Battlement by tapping it, adding at least seven
2. Activate Overgrown Battlement by paying , untapping itself
3. Repeat

Results

• Infinite green mana