Nim Deathmantle, Ashnod's Altar, and Shuri, Vibranium Technologist

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Shuri, Vibranium Technologist on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Shuri, adding
2. When Shuri dies, Nim Deathmantle triggers, causing you to pay to return Shuri from your graveyard to the battlefield and attach Nim Deathmantle to it
3. When Shuri 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