Carnage, Crimson Chaos, Saffi Eriksdotter, and Phyrexian Altar

Prerequisites

• Carnage, Crimson Chaos in hand
• Saffi Eriksdotter in the graveyard
• Phyrexian Altar on the battlefield

Steps

1. Cast Carnage by paying
2. When Carnage enters, it triggers, returning Saffi from your graveyard to the battlefield
3. Activate Saffi by sacrificing it, targeting Carnage
4. Activate Phyrexian Altar by sacrificing Carnage
5. When Carnage dies, Saffi triggers, returning Carnage from your graveyard to the battlefield
6. When Carnage enters, it triggers, returning Saffi from your graveyard to the battlefield
7. Resolve the Phyrexian Altar ability
8. Repeat from step 3

Results

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