Brotherhood Outcast, Unholy Indenture, and Yahenni, Undying Partisan

Prerequisites

• Brotherhood Outcast on the battlefield
• Unholy Indenture on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Brotherhood Outcast
2. When Brotherhood Outcast dies, Unholy Indenture triggers, returning Brotherhood Outcast from your graveyard to the battlefield
3. When Brotherhood Outcast enters the battlefield, it triggers, returning Unholy Indenture from your graveyard to the battlefield attached to Brotherhood Outcast
4. Resolve the Yahenni ability
5. Repeat

Results

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