There and Back Again | Song of the Worldsoul | Shrieking Drake

Cards

At the beginning of your precombat main phase,
There and Back Again triggers, creating a legendary 6/6 Smaug creature token, and causing you to sacrifice
There and Back Again.
Cast
Shrieking Drake by paying ({U} magic symbol) .
Song of the Worldsoul triggers, creating a copy of the Smaug token.
Put a Smaug token into your graveyard due to the legend rule.
When the Smaug dies, it triggers, creating fourteen Treasure tokens.
When
Shrieking Drake enters the battlefield, it triggers, returning itself to your hand from the battlefield.
Activate a Treasure by tapping and sacrificing it, adding ({U} magic symbol) .
Repeat from step 2.
Once you have infinite colored mana, you may use
Song of the Worldsoul's trigger to target any other token you control instead.