Metamorphosis Fanatic, Lagrella, the Magpie, and Yahenni, Undying Partisan

Prerequisites

• Metamorphosis Fanatic in hand
• Lagrella, the Magpie in the graveyard
• Yahenni, Undying Partisan on the battlefield
• available

Steps

1. Cast Metamorphosis Fanatic by paying
2. When Metamorphosis Fanatic enters, it triggers, returning Lagrella from your graveyard to the battlefield
3. When Lagrella enters, it triggers, exiling Metamorphosis Fanatic until Lagrella leaves the battlefield
4. Activate Yahenni by sacrificing Lagrella
5. When Lagrella leaves the battlefield, Metamorphosis Fanatic is returned from exile to the battlefield
6. Repeat from step 2
7. Resolve all Yahenni abilities

Results

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