Brotherhood Outcast, Phantom Train, and Kaya's Ghostform

Prerequisites

• Brotherhood Outcast on the battlefield
• Phantom Train on the battlefield
• Kaya's Ghostform on the battlefield

Steps

1. Activate Phantom Train 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 Phantom Train ability
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite +1/+1 counters on a creature