Mikaeus, the Unhallowed, Cauldron of Souls, Intruder Alarm, Animate Artifact, and Carrion Feeder

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Cauldron of Souls on the battlefield
• Intruder Alarm on the battlefield
• Animate Artifact on the battlefield
• Carrion Feeder on the battlefield
• Animate Artifact attached to Cauldron of Souls
• Cauldron of Souls does not have summoning sickness

Steps

1. Activate Carrion Feeder by sacrificing itself
2. When Carrion Feeder dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
3. When Carrion Feeder enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Resolve the Carrion Feeder ability, doing nothing
5. Activate Cauldron of Souls by tapping it, giving the creature persist until end of turn
6. Activate Carrion Feeder by sacrificing itself
7. When Carrion Feeder dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
8. When Carrion Feeder enters the battlefield, Intruder Alarm triggers, untapping all creatures
9. Resolve the Carrion Feeder ability, doing nothing
10. Repeat
11. If you control an additional nontoken, non-Human creature, you may instead sacrifice it to get infinite +1/+1 counters on Carrion Feeder

Results

• Infinite +1/+1 counters on Carrion Feeder
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of all creatures