Veinwitch Coven + Phyrexian Altar + Vengeful Bloodwitch

Veinwitch Coven

Phyrexian Altar

Vengeful Bloodwitch

How it works

1. Activate Phyrexian Altar by sacrificing the one-drop creature, adding .
2. When that creature dies, it and Vengeful Bloodwitch trigger.
3. Resolve the creature's ability, creating a creature token.
4. Resolve the Vengeful Bloodwitch ability, gaining at least one life and causing at least one opponent to lose at least one life.
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.