Xavier Sal, Infested Captain, Intruder Alarm, and Donatello, Way with Machines

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Intruder Alarm on the battlefield
• Donatello, Way with Machines on the battlefield

Steps

1. Activate Xavier Sal by tapping it and removing a counter from a permanent you control, creating a copy of an artifact creature token you control
2. When the creature token enters the battlefield, Intruder Alarm and Donatello trigger
3. Resolve the Intruder Alarm trigger, untapping all creatures
4. Resolve the Donatello trigger, putting a counter on it
5. Repeat

Results

• Infinite ETB
• Infinite copies of creature tokens you control
• Infinite creature tokens
• Infinite mana creatures you control can produce
• Infinite untap of creatures