Saffi Eriksdotter, Yahenni, Undying Partisan, and Shepherd of the Cosmos

Prerequisites

• Saffi Eriksdotter on the battlefield
• Yahenni, Undying Partisan on the battlefield
• Shepherd of the Cosmos on the battlefield

Steps

1. Activate Saffi by sacrificing it, targeting Shepherd of the Cosmos Activate Yahenni by sacrificing Shepherd of the Cosmos When Shepherd of the Cosmos dies, Saffi triggers, returning Shepherd of the Cosmos from your graveyard to the battlefield
2. When Shepherd of the Cosmos enters, it triggers, returning Saffi from your graveyard to the battlefield
3. Resolve the Yahenni ability
4. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers