Nim Deathmantle, Ashnod's Altar, and Mechanized Ninja Cavalry

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Mechanized Ninja Cavalry on the battlefield
• available

Steps

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

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers