Xavier Sal, Infested Captain, Intruder Alarm, and Master Biomancer

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Intruder Alarm on the battlefield
• Master Biomancer on the battlefield
• Xavier Sal does not have summoning sickness
• You control at least one nonlegendary creature token
• There is at least one counter on a permanent you control

Steps

1. Activate Xavier Sal's first ability by removing a counter from a permanent you control, creating a copy of a creature token you control that enters the battlefield with two +1/+1 counters on it due to Master Biomancer
2. When the creature token enters the battlefield, Intruder Alarm triggers, untapping all creatures
3. Repeat

Results

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