Cast Whim of Volrath with buyback by paying ({2} magic symbol) ({U} magic symbol) , targeting Harmonic Prodigy.
Orvar triggers twice and Harmonic Prodigy triggers once.
Resolve the Harmonic Prodigy trigger, giving it +1/+1 until end of turn.
Resolve the Orvar triggers, creating two token copies of Harmonic Prodigy.
Resolve Whim of Volrath, returning it to your hand.
Cast Whim of Volrath with buyback by paying ({2} magic symbol) ({U} magic symbol) , targeting any nonlegendary permanent you control that enters the battlefield untapped and that can tap to produce at least ({U} magic symbol) .
Orvar triggers four times, and each Harmonic Prodigy triggers three times.
Resolve all Harmonic Prodigy triggers, giving each Harmonic Prodigy +3/+3 until end of turn.
Resolve all Orvar triggers, creating four copies of the mana-producing permanent.
Resolve Whim of Volrath, returning it to your hand.
Activate three of the copies of the mana-producing permanent by tapping them, adding at least ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .