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}.
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}.
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.

Infinite colored mana

Infinite copies of tokens you control

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite storm count

Infinite Treasure tokens

There and Back Again

Song of the Worldsoul

Shrieking Drake

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 Ancestral Statue by paying {4}.
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 Ancestral Statue enters the battlefield, it triggers, returning itself to your hand from the battlefield.
Activate four Treasure tokens by tapping and sacrificing them, adding {4}.
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.

Ancestral Statue

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 Seething Anger with buyback by paying {3}{R}, targeting any creature you control.
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.
Resolve Seething Anger, giving a creature you control +3/+0 until end of turn and returning Seething Anger to your hand.
Activate four Treasure tokens by tapping and sacrificing them, adding {3}{R}.
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.

Infinite magecraft triggers

Infinite power for creatures you control until end of turn

Seething Anger

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 Searing Touch with buyback by paying {4}{R}, targeting any applicable target.
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.
Resolve Searing Touch, dealing 1 damage to any target and returning Searing Touch to your hand.
Activate five Treasure tokens by tapping and sacrificing them, adding {4}{R}.
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.

Infinite damage

Searing Touch

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 Man-o'-War by paying {2}{U}.
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 Man-o'-War enters the battlefield, it triggers, returning itself to your hand from the battlefield.
Activate three Treasure tokens by tapping and sacrificing them, adding {2}{U}.
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.

Combos with "Song of the Worldsoul"