Cast Myr Retriever for its emerge cost by paying {0} and sacrificing Workshop Assistant.
Glaring Fleshraker's first ability and Workshop Assistant trigger.
Resolve the Glaring Fleshraker trigger, creating a 0/1 Eldrazi Spawn creature token.
Resolve the Workshop Assistant trigger, returning Junk Diver from your graveyard to your hand.
When Myr Retriever enters the battlefield, Glaring Fleshraker's second ability triggers, dealing 1 damage to each opponent.
Activate an Eldrazi Spawn by sacrificing it, adding {C}.
Cast Junk Diver for its emerge cost by paying {1} and sacrificing Myr Retriever.
Glaring Fleshraker's first ability and Myr Retriever trigger.
Resolve the Glaring Fleshraker trigger, creating a 0/1 Eldrazi Spawn creature token.
Resolve the Myr Retriever trigger, returning Workshop Assistant from your graveyard to your hand.
When Junk Diver enters the battlefield, Glaring Fleshraker's second ability triggers, dealing 1 damage to each opponent.
Cast Workshop Assistant for its emerge cost by paying {0} and sacrificing Junk Diver.
Glaring Fleshraker's first ability and Junk Diver trigger.
Resolve the Glaring Fleshraker trigger, creating a 0/1 Eldrazi Spawn creature token.
Resolve the Junk Diver trigger, returning Myr Retriever from your graveyard to your hand.
When Workshop Assistant enters the battlefield, Glaring Fleshraker's second ability triggers, dealing 1 damage to each opponent.
Repeat.

Infinite creature LTB

Infinite creature ETB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite colorless mana

Infinite damage

Infinite storm count

Infinite creature tokens

Herigast, Erupting Nullkite

Myr Retriever

Junk Diver

Workshop Assistant

Glaring Fleshraker

Cast the creature with a generic mana cost by paying its mana cost or emerge cost.
When the creature enters the battlefield, Cloudstone Curio and Molten Echoes trigger.
Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand.
Resolve the Molten Echoes trigger, creating a token copy of the generic mana cost creature.
When the creature token enters the battlefield, Cloudstone Curio triggers, returning the nontoken generic mana cost creature from the battlefield to your hand.
Cast the generic mana cost creature for its emerge cost by sacrificing the creature token created in step 5, and by paying {0} as the token will have the same mana value.
Repeat from step 2.

Nonartifact, Nonlegendary Creature with a Generic Mana Cost

Cloudstone Curio

Molten Echoes

Cast the creature with a generic mana cost by paying its mana cost or emerge cost.
Birgi triggers, adding {R}.
When the creature enters the battlefield, Cloudstone Curio and Flameshadow Conjuring trigger.
Resolve the Cloudstone Curio trigger, choosing to return nothing to your hand.
Resolve the Flameshadow Conjuring trigger, choosing to pay {R} to create a token copy of the generic mana cost creature.
When the creature token enters the battlefield, Cloudstone Curio triggers, returning the nontoken generic mana cost creature from the battlefield to your hand.
Cast the generic mana cost creature for its emerge cost by sacrificing the creature token created in step 5, and by paying {0} as the token will have the same mana value.
Repeat from step 2.

Flameshadow Conjuring

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Cast Skitterbeam Batallion by paying {9}.
Brinelin triggers, returning the other creature with mana value 9 from the battlefield to your hnad.
When Skitterbeam Batallion enters the battlefield, it triggers, creating two token copies of itself.
Cast the other creature with mana value 9 for its emerge cost by paying {0} and sacrificing a Skitterbeam Batallion token.
Brinelin triggers, returning the nontoken Skitterbeam Batallion from the battlefield to your hand.
Cast Skitterbeam Batallion for its emerge cost by paying {0} and sacrificing a Skitterbeam Batallion token.
Repeat from step 2.

Creature with MV=9 that has a generic mana cost

Brinelin, the Moon Kraken

Skitterbeam Battalion

Combos with "Herigast, Erupting Nullkite"