Mikaeus, the Unhallowed, Ashcloud Phoenix, and Carrion Feeder

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Ashcloud Phoenix on the battlefield
• Carrion Feeder on the battlefield

Steps

1. Activate Carrion Feeder by sacrificing Ashcloud Phoenix
2. When Ashcloud Phoenix dies, it triggers, as well as its undying ability if it does not have a +1/+1 counter on it
3. Resolve the first trigger, returning it from your graveyard to the battlefield face-down
4. Resolve the second trigger, doing nothing
5. Activate Carrion Feeder by sacrificing Ashcloud Phoenix
6. When Ashcloud Phoenix dies, it triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
7. Resolve the Carrion Feeder abilities from steps 1 and 5, putting two +1/+1 counters on it
8. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite +1/+1 counters on Carrion Feeder