Fain, the Broker, Marvin, Murderous Mimic, and Devoted Druid

Prerequisites

• Fain, the Broker on the battlefield
• Marvin, Murderous Mimic on the battlefield
• Devoted Druid on the battlefield

Steps

1. Activate Marvin using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it
2. Activate Marvin using Fain's second ability by tapping it and removing a -1/-1 counter from it, creating a Treasure token
3. Repeat

Results

• Infinite +1/+1 counters on creatures you control
• Infinite ETB
• Infinite LTB
• Infinite Treasure tokens
• Infinite colored mana
• Infinite creature tokens
• Infinite death triggers
• Infinite sacrifice triggers