In Genshin Impact, after assisting Bona in purifying the Abyssal Corruption from the Chu'ulel Light Core, players must help her locate the Primal of Flame. Once found, Travelers must offer two Pyrophosphorites (obtained 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 begins The Other Side of the Sky Quest, requiring the collection of four Burning Firestones to acquire the Jade of Return.

How to Obtain the Four Burning Firestones

Burning Firestone #1

The first Burning Firestone is obtained by following these steps:

1. Reach Tonatiuh.
2. Wait for the cutscene with Bona to conclude; the Little One will retrieve the first Firestone.
3. Follow the Little One to the bridge.
4. Activate the mechanism to raise the lift.
5. Interact with the small Saurian.
6. Speak with Bona.
7. Watch the subsequent cutscene.

Burning Firestone #2

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

1. Rotate the right and left floating isle mechanisms.
2. Cross the extended bridge to the east.
3. Raise the lift.
4. Follow the Little One to the Firestone.
5. Collect a Common chest along the way.
6. Activate the mechanism to the right of the Firestone.
7. Climb the platforms to the upper level.
8. Defeat the enemy.
9. Collect an Exquisite chest.
10. Activate the mechanism to open the gate.
11. Descend to the small Saurian.
12. Open the locked door.
13. Tell the Little One, "Let’s return to the altar!"
14. Return to the Altar of Primal of Flame.

Burning Firestone #3

To obtain the third Burning Firestone:

1. Rotate the right and northern floating isle mechanisms.
2. Cross the bridge to the northern isle's lower level.
3. Follow the Little One.
4. Observe the Secret Source Sentinel carrying the Firestone to the southwestern isle.
5. Proceed to the northwestern edge.
6. Possess a Qucusaurus.
7. Fly towards the Pyroculus.
8. Activate the mechanism within the tower.
9. Remain as a Qucusaurus and fly to the unlocked door.
10. Activate the elevator to return to the upper level.
11. Interact with the small Saurian and follow it.
12. Activate the lift.
13. 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 to adjust the bridge's angle.
3. Glide to the northern isle's upper level.
4. Lower the lift.
5. Follow the Little One.
6. Tell it, "Let’s return to the altar!"
7. Defeat the enemies.
8. Again, tell the Saurian to return to the altar.
9. Collect a Precious chest.
10. Go to the Altar of Primal of Flame.

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