The Master, Formed Anew, and Carrion Feeder

Prerequisites

• The Master, Formed Anew on the battlefield
• Carrion Feeder on the battlefield
• Both the persist and undying creatures are in exile with at least one takeover counter on them
• The Master on the battlefield as a copy of either the persist or undying creature
• The Master does not have a +1/+1 counter on it if it is a copy of the undying creature, or a -1/-1 counter on it otherwise

Steps

1. Activate Carrion Feeder by sacrificing The Master
2. When The Master dies, if it was a copy of the undying creature, its undying ability triggers, returning it from your graveyard to the battlefield as a copy of the persist creature with a +1/+1 counter on it
3. Otherwise, if The Master was a copy of the persist creature, its persist ability triggers, returning it from your graveyard to the battlefield as a copy of the undying creature with a -1/-1 counter on it
4. Resolve the Carrion Feeder ability, putting a +1/+1 counter on it
5. Repeat

Results

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