Nim Deathmantle, Cathodion, and Phyrexian Altar

Prerequisites

• Nim Deathmantle on the battlefield
• Cathodion on the battlefield
• Phyrexian Altar on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing Cathodion, adding one mana of any color
2. Cathodion and Nim Deathmantle trigger
3. Resolve the Cathodion trigger, adding
4. Resolve the Nim Deathmantle trigger, causing you to pay to return Cathodion from your graveyard to the battlefield, and then attach Nim Deathmantle to it
5. Repeat

Results

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