After assisting Bona in purifying the Chu'ulel Light Core from Abyssal Corruption in 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 Location 1
The journey begins upon arrival at Tonatiuh. After the cutscene with Bona concludes, the Little One will retrieve the first Burning Firestone. Guide the Little One across the bridge (activating the lift mechanism as needed), interact with the Saurian, speak with Bona, and watch the subsequent cutscene.
Burning Firestone Location 2
The second Firestone is located on the northeastern isle. The retrieval process involves manipulating the floating isle mechanisms (both right and left), crossing the extended bridge, raising the lift, and following the Little One to the Firestone. Along the way, collect a Common chest. Activate the mechanism near the Firestone, ascend the platforms, defeat the enemy, and claim an Exquisite chest. Use the mechanism behind the chest to unlock a gate, descend to the Saurian, open the door, and instruct the Little One to return to the altar.
Burning Firestone Location 3
To obtain the third Burning Firestone: manipulate the right and northern floating isle mechanisms, cross the bridge to the lower level of the northern isle, follow the Little One, and observe the Secret Source Sentinel transporting the Firestone to the southwestern isle. Travel to the northwestern edge, inhabit a Qucusaurus, fly to the Pyroculus, activate the tower mechanism, transform into a Qucusaurus again, fly to the unlocked door, activate the elevator, interact with the Saurian, follow it, activate the lift, and return to the Altar of Primal of Flame.
Burning Firestone Location 4
The final Firestone resides on the upper level of the northwestern isle. Cross the northwestern bridge, enlist Bona's aid to raise the bridge, glide to the northern isle's upper level, lower the lift, follow the Little One, instruct it to return to the altar, defeat the enemies, and, after another request to the Saurian, collect a Precious chest before returning to the altar.
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 the completion of The Other Side of the Sky Quest, rewarding players with 50 Primogems.