Nim Deathmantle, Ashnod's Altar, and Silvergill Mentor

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Silvergill Mentor on the battlefield
• available

Steps

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