Necrogenesis + Void Attendant + Phyrexian Altar + Doubling Season

Necrogenesis

Void Attendant

Phyrexian Altar

Doubling Season

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 loop transforms graveyard management into a self-sustaining engine by cycling cards back and forth between exile and the graveyard. Doubling Season ensures that whenever Necrogenesis creates a Saproling or Void Attendant creates an Eldrazi Scion, you actually receive two tokens instead of one. Sacrificing those duplicated tokens to Phyrexian Altar provides the exact mana needed to fuel the next iteration, generating an endless cascade of creature sacrifices, enters-the-battlefield, and leaves-the-battlefield triggers.