Xavier Sal, Infested Captain, Intruder Alarm, and Arlinn, Voice of the Pack

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Intruder Alarm on the battlefield
• Arlinn, Voice of the Pack on the battlefield

Steps

1. Activate Arlinn's loyalty ability by removing two loyalty counters from it, creating a 2/2 Wolf creature token that enters the battlefield with a +1/+1 counter on it
2. Activate Xavier Sal's first ability by tapping it and removing the +1/+1 counter from the Wolf token, creating a copy of the Wolf token that enters the battlefield with a +1/+1 counter on it due to Arlinn
3. When the Wolf token enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Repeat from step 2

Results

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