Brotherhood Outcast, Shade's Form, and Bloodthrone Vampire

Prerequisites

• Brotherhood Outcast on the battlefield
• Shade's Form on the battlefield
• Bloodthrone Vampire on the battlefield

Steps

1. Activate Bloodthrone Vampire by sacrificing Brotherhood Outcast
2. When Brotherhood Outcast dies, Shade's Form triggers, returning Brotherhood Outcast from your graveyard to the battlefield
3. When Brotherhood Outcast enters the battlefield, it triggers, returning Shade's Form from your graveyard to the battlefield attached to Brotherhood Outcast
4. Resolve the Bloodthrone Vampire ability
5. Repeat

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinitely large creature until end of turn