Witch Engine, Corpse Dance, and Ashnod's Altar

Prerequisites

• Witch Engine on the battlefield
• Corpse Dance in hand
• Ashnod's Altar on the battlefield

Steps

1. Activate Witch Engine by tapping it, targeting any opponent
2. Holding priority, activate Ashnod's Altar by sacrificing Witch Engine, adding
3. Resolve the Witch Engine ability, adding and not giving control of Witch Engine to an opponent due to it no longer being on the battlefield
4. Cast Corpse Dance with buyback by paying , returning Witch Engine from your graveyard to the battlefield with haste, and returning Corpse Dance to your hand
5. Repeat

Results

• Infinite black mana
• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite magecraft triggers
• Infinite sacrifice triggers
• Infinite storm count