Necrogenesis + Void Attendant + Phyrexian Altar + Primal Vigor

Necrogenesis

Void Attendant

Phyrexian Altar

Primal Vigor

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 cunning loop turns the graveyards and exile zones into an engine for infinite tokens and mana, fueled entirely by the card-doubling power of Primal Vigor. You begin by using Necrogenesis to strip a creature from an opponent's graveyard, which Primal Vigor multiplies into a pair of Saproling tokens. Sacrificing those tokens to Phyrexian Altar provides the exact green and generic mana needed to activate Void Attendant, which feeds on an exiled card to return it to the graveyard and generate two Eldrazi Scions. Sacrificing those Scions back to Phyrexian Altar generates the surplus mana required to repeat the cycle, yielding infinite creature triggers and resources.