Red XIII, Proud Warrior, Kaya's Ghostform, and Phyrexian Altar

Prerequisites

• Red XIII, Proud Warrior on the battlefield
• Kaya's Ghostform on the battlefield
• Phyrexian Altar on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing Red XIII, adding
2. When Red XIII dies, Kaya's Ghostform triggers, returning Red XIII from your graveyard to the battlefield
3. When Red XIII enters the battlefield, it triggers, returning Kaya's Ghostform from your graveyard to your hand
4. Cast Kaya's Ghostform by paying , attaching it to Red XIII
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite storm count