Nim Deathmantle, Ashnod's Altar, and Seraph of the Scales

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Seraph of the Scales on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Seraph of the Scales, adding
2. When Seraph of the Scales dies, it and Nim Deathmantle trigger, Resolve the Seraph of the Scales trigger, creating two creature tokens
3. Holding priority, activate Ashnod's Altar by sacrificing a creature token, adding
4. Resolve the Nim Deathmantle trigger, causing you to pay to return Seraph of the Scales from your graveyard to the battlefield and attach Nim Deathmantle to it
5. Repeat

Results

• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers