Xavier Sal, Infested Captain, Haunted One, Intruder Alarm, and Carrion Feeder

Prerequisites

• Xavier Sal, Infested Captain on the battlefield
• Haunted One on the battlefield
• Intruder Alarm on the battlefield
• Carrion Feeder on the battlefield
• There is at least one counter on a permanent you control except Xavier Sal
• Xavier Sal does not have summoning sickness
• You control at least one additional nontoken Human, Fungus and/or Pirate that has no more than one +1/+1 counter on it

Steps

1. Activate Xavier Sal's first ability by tapping it and removing a +1/+1 counter from the additional nontoken Human, Fungus and/or Pirate if it has one, or any counter from another permanent you control otherwise
2. Xavier Sal triggers, causing it and all other creatures you control that share a creature type with it to get +2/+0 and gain undying until end of turn
3. Resolve the Xavier Sal ability, causing you to populate
4. Activate Carrion Feeder by sacrificing the additional Human, Fungus and/or Pirate
5. When the creature dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. When the creature enters the battlefield, Intruder Alarm triggers, untapping all creatures
7. Resolve the Carrion Feeder ability, putting a +1/+1 counter on it
8. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite untap of all creatures
• Infinite mana creatures you control can produce
• Infinite +1/+1 counters on Carrion Feeder
• Infinitely powerful Humans, Fungi and Pirates you control until end of turn