Cast Walking Ballista by paying {0}.
Walking Ballista enters and dies as a state-based action due to having 0 toughness.
Metastatic Evangel triggers, causing you to proliferate and put a +1/+1 counter on Evolution Witness.
Evolution Witness triggers, returning Walking Ballista from your graveyard to your hand.
Repeat.

Infinite LTB

Infinite ETB

Infinite death triggers

Infinite storm count

Infinite proliferate

Metastatic Evangel

Evolution Witness

Walking Ballista

Activate Aethergeode Miner by paying {E}{E}, blinking it.
When Aethergeode Miner enters the battlefield, Metastatic Evangel and Decoction Module trigger.
Resolve the Decoction Module trigger, causing you to get {E}.
Resolve the Metastatic Evangel trigger, causing you to proliferate and get {E}.
Repeat.

Aethergeode Miner

Decoction Module

Cast Shrieking Drake by paying {U}.
When Shrieking Drake enters the battlefield, it and Metastatic Evangel trigger.
Resolve the Shrieking Drake trigger, returning it from the battlefield to your hand.
Resolve the Metastatic Evangel trigger, putting a +1/+1 counter on Crystalline Crawler.
Activate Crystalline Crawler's first ability by removing a +1/+1 counter from it, adding {U}.
Repeat.

Shrieking Drake

Crystalline Crawler

Cast Shrieking Drake by paying {U}.
When Shrieking Drake enters the battlefield, it and Metastatic Evangel trigger.
Resolve the Shrieking Drake trigger, returning it from the battlefield to your hand.
Resolve the Metastatic Evangel trigger, putting a charge counter on Pentad Prism.
Activate Pentad Prism by removing a charge counter from it, adding {U}.
Repeat.

Pentad Prism

Cast the creature by paying {0}.
When the creature enters the battlefield, Metastatic Evangel triggers, and Cloudstone Curio triggers if the creature was not an artifact.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing to your hand.
Resolve the Metastatic Evangel trigger, causing you to put a +1/+1 counter on Basking Broodscale.
Basking Broodscale triggers, creating a 0/1 Eldrazi Spawn creature token.
When the Eldrazi Spawn enters the battlefield, Cloudstone Curio triggers, returning the creature with mana cost {0} from the battlefield to your hand.
Repeat.

Infinite +1/+1 counters on Scurry Oak

Infinite colorless mana

Infinite creature tokens

Creature with Mana Cost Equal to {0}

Cloudstone Curio

Basking Broodscale

Cast the creature by paying {0}.
When the creature enters the battlefield, Metastatic Evangel triggers, and Cloudstone Curio triggers if the creature was not an artifact.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing to your hand.
Resolve the Metastatic Evangel trigger, causing you to put a +1/+1 counter on Scurry Oak.
Scurry Oak triggers, creating a 1/1 Squirrel creature token.
When the Squirrel enters the battlefield, Cloudstone Curio triggers, returning the creature with mana cost {0} from the battlefield to your hand.
Repeat.

Scurry Oak

Cast Sakura-Tribe Elder by paying its mana cost if it is in your hand. Otherwise, activate Tayam by paying {3} and removing three counters from creatures you control, causing you to mill three cards and return Sakura-Tribe Elder from your graveyard to the battlefield with a vigilance counter on it.
When Sakura-Tribe Elder enters the battlefield, Metastatic Evangel triggers, causing you to put a +1/+1 counter on Cryptic Trilobite and Basking Broodscale and a vigilance counter on Sakura-Tribe Elder.
Basking Broodscale triggers, creating a 0/1 Eldrazi Spawn creature token that enters with a vigilance counter on it.
Activate Cryptic Trilobite by removing a +1/+1 counter from it, adding {C}{C} that can only be spent to activate abilities.
Activate the Eldrazi Spawn by sacrificing it, adding {C}.
Activate Tayam by paying {3}, removing both vigilance counters from Sakura-Tribe Elder and another counter from a creature you control.
Holding priority, activate Sakura-Tribe Elder by sacrificing it.
Resolve the Tayam ability, causing you to mill three cards and return Sakura-Tribe Elder from your graveyard to the battlefield with a vigilance counter on it.
Repeat from step 2.
Repeat.

Infinite sacrifice triggers

Infinite self-mill

Put all basic land cards from your library onto the battlefield tapped

Tayam, Luminous Enigma

Cryptic Trilobite

Sakura-Tribe Elder

Cast the creature by paying {0}.
When the creature enters the battlefield, Metastatic Evangel triggers, and Cloudstone Curio triggers if the creature was not an artifact.
Resolve the Cloudstone Curio trigger, if applicable, choosing to return nothing to your hand.
Resolve the Metastatic Evangel trigger, causing you to put a +1/+1 counter on Herd Baloth.
Herd Baloth triggers, creating a 4/4 Beast creature token.
When the Beast enters the battlefield, Cloudstone Curio triggers, returning the creature with mana cost {0} from the battlefield to your hand.
Repeat.

Herd Baloth

Cast Shrieking Drake by paying {U}.
When Shrieking Drake enters the battlefield, it and Metastatic Evangel trigger.
Resolve the Shrieking Drake trigger, returning it from the battlefield to your hand.
Resolve the Metastatic Evangel trigger, putting a charge counter on Gemstone Array.
Activate Gemstone Array's second ability by removing a charge counter from it, adding {U}.
Repeat.

Gemstone Array

Cast Mikaeus either from your hand or from the command zone by paying {W} plus commander tax, if applicable.
Mikaeus enters the battlefield and dies as a state-based action due to having 0 toughness.
Metstatic Evangel and Magnanimous Magistrate trigger.
Resolve the Metastatic Evangel trigger, putting a reprieve counter on Magnanimous Magistrate.
Resolve the Magnanimous Magistrate trigger, removing a reprieve counter from it and returning Mikaeus from your graveyard to the battlefield.
Repeat

Mikaeus, the Lunarch

Magnanimous Magistrate

Cast Accursed Centaur from your hand by paying {B}.
When Accursed Centaur enters the battlefield, it and Metastatic Evangel trigger.
Resolve the Metastatic Evangel trigger, putting a repreive counter on Magnanimous Magistrate.
Resolve the Accursed Centaur trigger, sacrificing it.
Magnanimous Magistrate triggers, causing you to remove a reprieve counter from it and return Accursed Centaur from your graveyard to the battlefield.
Repeat from step 2.

Combos with "Metastatic Evangel"