The Master, Formed Anew, and Yahenni, Undying Partisan

Prerequisites

• The Master, Formed Anew on the battlefield
• Yahenni, Undying Partisan on the battlefield
• undefined

Steps

1. Activate Yahenni 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 Yahenni ability
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers