Archon of Falling Stars, Gift of Immortality, and Phyrexian Altar

Prerequisites

• Archon of Falling Stars on the battlefield
• Gift of Immortality on the battlefield
• Phyrexian Altar on the battlefield
• Gift of Immortality attached to Archon of Falling Stars

Steps

1. Activate Phyrexian Altar by sacrificing Archon of Falling Stars, adding one mana of any color
2. Archon of Falling Stars dies, triggering itself and Gift of Immortality
3. Resolve the Gift of Immortality trigger, returning Archon of Falling Stars from your graveyard to the battlefield
4. Resolve the Archon of Falling Stars trigger, returning Gift of Immortality from your graveyard to the battlefield attached to Archon of Falling Stars
5. Repeat

Results

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