Brotherhood Outcast, Umbral Collar Zealot, and Kaya's Ghostform

Prerequisites

• Brotherhood Outcast on the battlefield
• Umbral Collar Zealot on the battlefield
• Kaya's Ghostform on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Brotherhood Outcast
2. When Brotherhood Outcast dies, Kaya's Ghostform triggers, returning Brotherhood Outcast from your graveyard to the battlefield
3. When Brotherhood Outcast enters the battlefield, it triggers, returning Kaya's Ghostform from your graveyard to the battlefield attached to Brotherhood Outcast
4. Resolve the Umbral Collar Zealot ability
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite surveil 1