Nim Deathmantle, Ashnod's Altar, and Sally Pride, Lioness Leader

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Sally Pride, Lioness Leader on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Sally Pride, adding
2. When Sally Pride dies, Nim Deathmantle triggers, causing you to pay to return Sally Pride from your graveyard to the battlefield and attach Nim Deathmantle to it
3. When Sally Pride enters, it triggers, creating at least one 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