Veinwitch Coven, Moldervine Reclamation, and Phyrexian Altar

Prerequisites

• Veinwitch Coven on the battlefield
• Moldervine Reclamation on the battlefield
• Phyrexian Altar on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing the one-drop creature, adding
2. When that creature dies, it and Moldervine Reclamation trigger
3. Resolve the creature's ability, creating a creature token
4. Resolve the Moldervine Reclamation ability, gaining 1 life and drawing a card
5. When you gain life, Veinwitch Coven triggers, causing you to pay to return the one-drop creature from your graveyard to your hand
6. Activate Phyrexian Altar by sacrificing the token creature, adding one colored mana
7. Cast the creature by paying one mana
8. Repeat

Results

• Infinite card draw
• Infinite draw triggers
• Near-infinite creature ETB
• Near-infinite creature LTB
• Near-infinite creature sacrifice triggers
• Near-infinite death triggers
• Near-infinite lifegain