Colfenor, the Last Yew, Saffi Eriksdotter, Pitiless Plunderer, and Ashnod's Altar

Prerequisites

• Colfenor, the Last Yew on the battlefield
• Saffi Eriksdotter on the battlefield
• Pitiless Plunderer on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Saffi Eriksdotter by sacrificing it targeting Colfenor
2. Colfenor and Pitiless Plunderer trigger
3. Let the Colfenor trigger resolve, declining to return anything
4. Resolve the Pitiless Plunderer trigger, creating a Treasure token
5. Resolve the Saffi Eriksdotter ability, creating a delayed trigger that will return Colfenor to the battlefield when it dies
6. Activate Ashnod's Altar by sacrificing Colfenor, adding
7. Colfenor, Pitiless Plunderer, and Saffi Eriksdotter trigger
8. Resolve the Colfenor trigger, returning Saffi Eriksdotter to your hand
9. Resolve the Pitiless Plunderer trigger, creating a Treasure token
10. Resolve the Saffi Eriksdotter trigger, returning Colfenor to the battlefield
11. Cast Saffi Eriksdotter by sacrificing the two Treasure tokens
12. Repeat

Results

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