Your opponents control at least three artifacts and/or enchantments.
({1} magic symbol) ({WU} magic symbol) ({R} magic symbol) ({R} magic symbol) , plus commander tax if applicable, plus one additional red, white, or blue mana if opponents control exactly three artifacts and/or enchantments available.
Steps
Cast Vadrok for its mutate cost by paying ({1} magic symbol) ({WU} magic symbol) ({R} magic symbol) ({R} magic symbol) , merging it under Dockside Extortionist.
The Dockside Extortionist mutated creature's ability from Vadrok triggers, casting Twinflame from your graveyard without paying its mana cost.
Resolve Twinflame, creating a token copy of the Dockside Extortionist mutated creature with haste.
The token copy of the Dockside Extortionist mutated creature triggers, creating at least three Treasure tokens.
Activate three Treasure tokens by tapping and sacrificing them, adding ({U} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Cast Snap by paying ({1} magic symbol) ({U} magic symbol) , returning the nontoken Dockside Extortionist and Vadrok from the battlefield to your hand and untapping two lands you control.
Cast Vadrok for its mutate cost by paying ({1} magic symbol) ({WU} magic symbol) ({R} magic symbol) ({R} magic symbol) , merging it under the token Dockside Extortionist mutated creature.
The token Dockside Extortionist mutated creature triggers once for each of its Vadrok abilities.
Resolve one of these triggers, casting Twinflame from your graveyard without paying its mana cost.
Resolve Twinflame, creating a token copy of the Dockside Extortionist mutated creature with haste.
The token copy of the Dockside Extortionist mutated creature triggers, creating at least three Treasure tokens.
Activate three Treasure tokens by tapping and sacrificing them, adding ({U} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Resolve a second trigger from step 8, casting Snap from your graveyard without paying its mana cost, targeting the mutated creature that includes the nontoken Vadrok.
Resolve Snap, returning Vadrok from the battlefield to your hand as well as multiple token creatures which cease to exist, and untapping two lands you control.
Resolve any remaining triggers from step 8, casting any noncreature cards with mana value 3 or less that were not already cast since step 8 from your graveyard without paying their casting costs.
Repeat from step 7, adding one additional token Vadrok to each new iteration of the Dockside Extortionist mutated creature token.
Results
Infinite casts of all noncreature cards with mana value 3 or less in your graveyard.