Nim Deathmantle, Ashnod's Altar, and Sling-Gang Lieutenant

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Sling-Gang Lieutenant on the battlefield
• available

Steps

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

Results

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