Go-Shintai of Life's Origin, There and Back Again, Clock of Omens, Contagion Engine, and Mycosynth Lattice Combo

Prerequisites

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
If you control two Smaugs, put one into your graveyard due to the legend rule
If you do, the Smaug that died triggers, creating fourteen Treasure tokens
If you made Treasures this way, activate nine Treasures by tapping and sacrificing them, adding
Activate Go-Shintai by paying and tapping it, returning There and Back Again from your graveyard to the battlefield with a lore counter on it
There and Back Again's first chapter ability triggers, causing the Ring to tempt you
Activate Contagion Engine by paying and tapping it, putting two lore counters on There and Back Again
There and Back Again's second and third chapter abilities trigger
Holding priority, activate Clock of Omens twice by tapping four artifacts, untapping Contagion Engine and Go-Shintai
Resolve the second There and Back Again trigger, causing you to search your library for a Mountain and put it onto the battlefield
Resolve the third There and Back Again trigger, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again
Repeat from step 3