At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
There and Back Again's third chapter ability triggers, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again.
Activate Flamewright's first ability by paying 1 and tapping it, creating a 1/1 Construct creature token.
Activate Blade of Shared Souls' equip ability by paying 2, attaching it to the Construct token.
Blade of Shared Souls triggers, causing the Construct to become a copy of Smaug for as long as Blade of Shared Souls is attached to it.
Put the Construct token into your graveyard due to the legend rule.
When the Construct dies, it triggers, creating fourteen Treasure artifact tokens.
Activate four Treasures by tapping and sacrificing them, adding 3.
Activate Freed from the Real's second ability by paying , untapping Flamewright.
Repeat from step 3.
Once you have infinite mana, you may simply tap and untap Flamewright to get infinite Construct tokens, and then use its second ability to sacrifice them for infinite damage.
By advancing There and Back Again to its final chapter, you conjure the mighty Smaug, whose eventual demise yields a massive hoard of fourteen Treasure tokens. To bypass the legend rule and harness this power, you equip Blade of Shared Souls to a 1/1 token created by Flamewright, instantly turning that humble Construct into a copy of the legendary Dragon. As state-based actions send the copied Dragon to the graveyard, it triggers its death ability to spawn those fourteen Treasures. You can then use Freed from the Real to untap Flamewright, feeding the mana generated by the Treasures to loop the process infinitely for infinite mana, tokens, and damage.