Nim Deathmantle, Ashnod's Altar, and Mausoleum Guard

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Mausoleum Guard on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Mausoleum Guard, adding
2. When Mausoleum Guard dies, it and Nim Deathmantle trigger, Resolve the Mausoleum Guard trigger, creating two 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 Mausoleum Guard 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