Perigee Beckoner, Yahenni, Undying Partisan, and Metamorphosis Fanatic

Prerequisites

• Perigee Beckoner in hand
• Yahenni, Undying Partisan on the battlefield
• Metamorphosis Fanatic on the battlefield

Steps

1. Cast Perigee Beckoner for its warp cost by paying
2. When Perigee Beckoner enters, it triggers, targeting Metamorphosis Fanatic
3. Activate Yahenni by sacrificing Perigee Beckoner
4. Activate Yahenni by sacrificing Metamorphosis Fanatic
5. When Metamorphosis Fanatic dies, it triggers, returning itself from your graveyard to the battlefield tapped
6. When Metamorphosis Fanatic enters, it triggers, returning Perigee Beckoner from your graveyard to the battlefield
7. When Perigee Beckoner enters, it triggers, targeting Metamorphosis Fanatic
8. Resolve the Yahenni ability from step 4
9. Repeat from step 3

Results

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