Devoted Druid, and Luxior, Giada's Gift

Prerequisites

• Devoted Druid on the battlefield
• Luxior, Giada's Gift on the battlefield
• Luxior attached to Devoted Druid
• Devoted Druid does not have summoning sickness

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 it
3. Because Luxior gives Devoted Druid +1/+1 for each counter on it, Devoted Druid's toughness remains unchanged
4. Repeat

Results

• Infinite green mana