Lotus Field and Azorius Chancery on the battlefield.
You control an additional non-Human creature that can be cast for ({0} magic symbol) .
({1} magic symbol) ({U} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Cast Snap by paying ({1} magic symbol) ({U} magic symbol) , returning the additional creature to your hand and untapping Lotus Field and Azorius Chancery.
Activate Lotus Field and the land by tapping them, adding at least ({1} magic symbol) ({WU} magic symbol) ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Cast the additional creature by paying ({0} magic symbol) .
Cast Vadrok for its mutate cost by paying ({1} magic symbol) ({WU} magic symbol) ({R} magic symbol) ({R} magic symbol) plus commander tax if applicable, mutating it under the additional creature.
The mutated creature's ability from Vadrok triggers, casting Snap from your graveyard without paying its mana cost.
Resolve Snap, returning both cards that compose the mutated creature from the battlefield to your hand and untapping Lotus Field and Azorius Chancery.