Requires

There and Back Again must be on the battlefield. Blade of Shared Souls must be on the battlefield. Flamewright must be on the battlefield. Freed from the Real must be on the battlefield. There and Back Again has exactly two lore counters on it. Flamewright does not have summoning sickness. Freed from the Real attached to Flamewright. Mana needed:

Steps

1. At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
2. 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.
3. Activate Flamewright's first ability by paying and tapping it, creating a 1/1 Construct creature token.
4. Activate Blade of Shared Souls' equip ability by paying , attaching it to the Construct token.
5. 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.
6. Put the Construct token into your graveyard due to the legend rule.
7. When the Construct dies, it triggers, creating fourteen Treasure artifact tokens.
8. Activate four Treasures by tapping and sacrificing them, adding .
9. Activate Freed from the Real's second ability by paying , untapping Flamewright.
10. Repeat from step 3.
11. 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.

Results