Activate Extruder by sacrificing Myr Moonvessel, targeting Evolution Witness.
When Myr Moonvessel dies, it triggers, adding {C}.
Evolution Witness triggers, returning Myr Moonvessel from your graveyard to your hand.
Cast Myr Moonvessel by paying its mana cost.
Repeat.

Infinite creature LTB

Infinite creature ETB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite storm count

Infinite +1/+1 counters on a creature

Evolution Witness

Extruder

Myr Moonvessel

Activate Extruder by sacrificing Cathodion, targeting Evolution Witness.
When Cathodion dies, it triggers, adding {C}{C}{C}.
Evolution Witness triggers, returning Cathodion from your graveyard to your hand.
Cast Cathodion by paying its mana cost.
Repeat.

Cathodion

Activate Extruder by sacrificing Su-Chi Cave Guard, targeting Evolution Witness.
When Su-Chi Cave Guard dies, it triggers, adding eight {C}.
Evolution Witness triggers, returning Su-Chi Cave Guard from your graveyard to your hand.
Cast Su-Chi Cave Guard by paying its mana cost.
Repeat.

Su-Chi Cave Guard

Activate Extruder by sacrificing Su-Chi, targeting Evolution Witness.
When Su-Chi dies, it triggers, adding {C}{C}{C}{C}.
Evolution Witness triggers, returning Su-Chi from your graveyard to your hand.
Cast Su-Chi by paying its mana cost.
Repeat.

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