Scarecrone, Thornbite Staff, Su-Chi, and Ashnod's Altar

Prerequisites

• Scarecrone on the battlefield
• Thornbite Staff on the battlefield
• Su-Chi on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Su-Chi, adding
2. Su-Chi dies, triggering itself and Scarecrone
3. Resolve the Su-Chi trigger, adding
4. Resolve the Scarecrone trigger, untapping it
5. Activate Scarecrone's second ability by paying and tapping it, returning Su-Chi from your graveyard to the battlefield
6. Repeat

Results

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