After assisting Bona in purifying the Chu'ulel Light Core from Abyssal Corruption within Genshin Impact, players must aid her in locating the Primal of Flame. Once found, Travelers must present two Pyrophosphorites – acquired during the Palace of the Vision Serpent Quest – to the Altar of Primal of Flame.

This offering opens a path to Tonatiuh, a floating island above Ochkanatlan's Cradle of Fleeting Dreams. Reaching Tonatiuh completes the To the Sky-Road Quest and initiates The Other Side of the Sky Quest, requiring Travelers to gather four Burning Firestones to obtain the Jade of Return.

Acquiring the Four Burning Firestones in Genshin Impact

Burning Firestone #1

The journey to the first Burning Firestone on Tonatiuh involves:

1. Reaching Tonatiuh.
2. Waiting for the Bona cutscene to conclude; the Little One will retrieve the first Firestone.
3. Following the Little One to the bridge.
4. Activating the bridge mechanism to raise the lift.
5. Interacting with the small Saurian.
6. Speaking with Bona.
7. Watching another cutscene.

Burning Firestone #2

The second Burning Firestone is located on the northeastern isle. The steps are:

1. Rotating the right floating isle mechanism.
2. Rotating the left floating isle mechanism.
3. Proceeding east across the extended bridge.
4. Raising the lift.
5. Following the Little One to the Firestone.
6. Obtaining the Common chest en route.
7. Activating the mechanism to the right of the Firestone.
8. Ascending the platforms to the upper level.
9. Defeating the enemy.
10. Collecting the Exquisite chest atop the tower.
11. Activating the mechanism to open the gate.
12. Descending to the small Saurian.
13. Opening the locked door.
14. Instructing the Little One: "Let's return to the altar!"
15. Returning to the Altar of Primal of Flame.

Burning Firestone #3

To obtain the third Burning Firestone:

1. Rotate the right floating isle mechanism.
2. Rotate the northern floating isle mechanism.
3. Cross the bridge to the lower level of the northern isle.
4. Follow the Little One.
5. Observe the Secret Source Sentinel transporting the Firestone to the southwestern isle.
6. Proceed to the northwestern edge.
7. Transform into a Qucusaurus.
8. Fly towards the Pyroculus.
9. Activate the mechanism within the tower.
10. Transform into a Qucusaurus again.
11. Fly to the unlocked door.
12. Activate the elevator to return to the upper level.
13. Interact with the small Saurian and follow it.
14. Activate the lift.
15. Return to the Altar of Primal of Flame.

Burning Firestone #4

The final Burning Firestone is on the northwestern isle's upper level:

1. Cross the northwestern bridge.
2. Request Bona's assistance to raise the bridge.
3. Glide to the upper level of the northern isle.
4. Lower the lift.
5. Follow the Little One.
6. Instruct it: "Let's return to the altar!"
7. Defeat the enemy.
8. Again, instruct the Saurian to return to the altar.
9. Collect the Precious chest.
10. Proceed to the Altar of Primal of Flame.

Offering all four Firestones to the Altar completes The Flowing Primal Flame Quest, triggering a cutscene transforming the Jade of Return into a Golden Entreaty. The Dragon of the City of Flowing Ash then appears, leading to the Nursery of Nightmares island and completion of The Other Side of the Sky Quest, rewarding 50 Primogems.