Nim Deathmantle, Ashnod's Altar, and Peema Outrider

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Peema Outrider on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Peema Outrider, adding
2. When Peema Outrider dies, Nim Deathmantle triggers, causing you to pay to return Peema Outrider from your graveyard to the battlefield, and attach Nim Deathmantle to it
3. When Peema Outrider enters the battlefield, its fabricate ability triggers, creating a 1/1 Servo artifact creature token
4. Activate Ashnod's Altar by sacrificing the Servo, adding
5. Repeat

Results

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