Necrogenesis + Void Attendant + Phyrexian Altar + Parallel Lives

Necrogenesis

Void Attendant

Phyrexian Altar

Parallel Lives

How it works

1. Activate Necrogenesis by paying 2, exling a creature card from an opponent's graveyard and creating two 1/1 Saproling creature tokens.
2. Activate Phyrexian Altar twice by sacrificing the Saprolings, adding 1.
3. Activate Void Attendant by paying 1 and putting a card from an opponent's exile into their graveyard, creating two 1/1 Eldrazi Scion creature tokens.
4. Activate Phyrexian Altar twice by sacrificing the Eldrazi Scions, adding 2.
5. Repeat.

This clever loop turns the graveyard into a revolving door of token generation, sustained entirely by the mana-generating power of Phyrexian Altar. You begin by using Necrogenesis to exile a creature from an opponent's graveyard, while Parallel Lives doubles the resulting tokens into a pair of Saprolings. Those tokens are promptly fed to Phyrexian Altar to generate the exact green mana needed to fund Void Attendant. Void Attendant then recycles a card from exile back to that same opponent's graveyard, creating Eldrazi Scions that Parallel Lives multiplies once more. Sacrificing those Scions back to Phyrexian Altar nets you extra mana to repeat the cycle infinitely, fueling endless sacrifices, enters-the-battlefield triggers, and leaving-the-battlefield triggers.