Nim Deathmantle, Ashnod's Altar, and Harmonious Archon

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Harmonious Archon on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Harmonious Archon, adding
2. When Harmonious Archon dies, Nim Deathmantle triggers, causing you to pay to return Harmonious Archon from your graveyard to the battlefield, and attach Nim Deathmantle to it
3. When Harmonious Archon enters the battlefield, it triggers, creating two 1/1 Human creature tokens
4. Activate Ashnod's Altar by sacrificing a Human, adding
5. Repeat

Results

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