Devoted Druid, and Swift Reconfiguration

Prerequisites

• Devoted Druid on the battlefield
• Swift Reconfiguration on the battlefield
• Swift Reconfiguration attached to Devoted Druid

Steps

1. Activate Devoted Druid's first ability by tapping it, adding
2. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping itself
3. Repeat

Results

• Infinite green mana