Nim Deathmantle, Ashnod's Altar, and Grave Titan

Prerequisites

• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Grave Titan on the battlefield
• available

Steps

1. Activate Ashnod's Altar by sacrificing Grave Titan, adding
2. When Grave Titan dies, Nim Deathmantle triggers, causing you to pay to return Grave Titan from your graveyard to the battlefield and attach Nim Deathmantle to it
3. When Grave Titan enters, it triggers, creating two creature tokens
4. Activate Ashnod's Altar by sacrificing a creature token, adding
5. Repeat

Results

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