Xavier Sal, Infested Captain, Intruder Alarm, and Godtracker of Jund

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Intruder Alarm on the battlefield
• Godtracker of Jund on the battlefield
• You control at least one creature token with base power 5 or greater
• Xavier Sal does not have summoning sickness
• There is a removable counter on a permanent you control

Steps

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

Results

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