Sprout Swarm + Pitiless Plunderer + Utopia Mycon + Primal Vigor

Sprout Swarm

Pitiless Plunderer

Utopia Mycon

Primal Vigor

How it works

1. Cast Sprout Swarm with buyback by paying 4, creating two 1/1 Saproling creature tokens.
2. Activate Utopia Mycon twice by sacrificing the Saprolings, adding 1.
3. When the Saprolings die, Pitiless Plunderer triggers twice, creating four Treasure artifact tokens.
4. Activate three Treasures by tapping and sacrificing them, adding 3.
5. Repeat.
6. Once you have infinite Treasure tokens and colored mana, you may forego sacrificing the Saproling tokens.

This clever loop turns a modest green instant into a self-sustaining token factory by leveraging a cascade of token doublers and death triggers. You kickstart the engine by casting Sprout Swarm with its buyback cost, which Primal Vigor supercharges to instantly yield a pair of Saproling tokens. Those fresh bodies immediately feed into Utopia Mycon and Pitiless Plunderer, converting your casualties into a surge of colored mana and multiple Treasure tokens. By converting those Treasures back into mana to pay for the next casting of Sprout Swarm, you completely refund the spell's cost while letting Primal Vigor rapidly multiply your board state into an infinite sea of resources.