Workhorse, Nim Deathmantle, Ashnod's Altar, and Purphoros, God of the Forge

Prerequisites

• Workhorse on the battlefield
• Nim Deathmantle on the battlefield
• Ashnod's Altar on the battlefield
• Purphoros, God of the Forge on the battlefield
• Nim Deathmantle attached to Workhorse

Steps

1. Activate Workhorse by removing four +1/+1 counters, adding
2. Activate Ashnod's Altar by sacrificing Workhorse, adding
3. Workhorse dies, triggering Nim Deathmantle, causing you to pay to return Workhorse from your graveyard to the battlefield, and attach Nim Deathmantle to it
4. Workhorse enters the battlefield with four +1/+1 counters on it
5. Purphoros triggers, dealing 2 damages to each opponent
6. Repeat

Results

• Infinite colorless mana
• Infinite damage
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers