Yahenni, Undying Partisan, and Cayth, Famed Mechanist

Prerequisites

• Yahenni, Undying Partisan on the battlefield
• Cayth, Famed Mechanist on the battlefield

Steps

1. Activate Yahenni by sacrificing the persist creature
2. When the persist creature dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When the persist creature enters the battlefield, its fabricate ability triggers, putting a +1/+1 counter on it
4. Resolve the Yahenni ability, giving it indestructible until end of turn
5. Repeat

Results

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