Xavier Sal, Infested Captain, Saproling Burst, and Intruder Alarm

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Saproling Burst on the battlefield
• Intruder Alarm on the battlefield
• Xavier Sal does not have summoning sickness
• Saproling Burst has at least two fade counters on it

Steps

1. Activate Saproling Burst by removing a fade counter from it, creating a */* Saproling creature token
2. When the Saproling enters the battlefield, Intruder Alarm triggers, untapping all creatures
3. Activate Xavier Sal's second ability by tapping it and sacrificing the Saproling, putting a fade counter on Saproling Burst
4. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite proliferate
• Infinite sacrifice triggers
• Infinite untap of all creatures