Nim Deathmantle, Ashnod's Altar, and Nested Shambler

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Nested Shambler on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Nested Shambler, adding
2. When Nested Shambler dies, it and Nim Deathmantle trigger, Resolve the Nested Shambler trigger, creating at least three creature tokens
3. Holding priority, activate Ashnod's Altar by sacrificing a creature token, adding
4. Resolve the Nim Deathmantle trigger, causing you to pay to return Nested Shambler from your graveyard to the battlefield and attach Nim Deathmantle to it
5. Repeat

Results

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