Saffi Eriksdotter, Eternal Witness, Aluren, and Phyrexian Altar

Prerequisites

• Saffi Eriksdotter on the battlefield
• Eternal Witness on the battlefield
• Aluren on the battlefield
• Phyrexian Altar on the battlefield

Steps

1. Activate Saffi by sacrificing it, targeting Eternal Witness
2. Activate Phyrexian Altar by sacrificing Eternal Witness, adding one mana of any color
3. When Eternal Witness dies, Saffi triggers, returning it from your graveyard to the battlefield
4. When Eternal Witness enters the battlefield, it triggers, returning Saffi from your graveyard to your hand
5. Cast Saffi by paying due to Aluren
6. Repeat

Results

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