Nim Deathmantle, Ashnod's Altar, and Phyrexian Triniform

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Phyrexian Triniform on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Phyrexian Triniform, adding
2. When Phyrexian Triniform dies, it and Nim Deathmantle trigger, Resolve the Phyrexian Triniform trigger, creating 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 Phyrexian Triniform from your graveyard to the battlefield and attach Nim Deathmantle to it
5. Repeat

Results

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