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.

Gathering the Four Burning Firestones:

Burning Firestone #1

The first Burning Firestone is obtained after a cutscene with Bona on Tonatiuh. The Little One will retrieve it; follow it across a raised lift to interact with a Saurian and Bona, triggering another cutscene.

Burning Firestone #2

The second Firestone is on the northeastern isle. Activate floating isle mechanics to extend bridges, raise a lift, and follow the Little One. Along the way, collect a Common chest, activate a mechanism to reach a tower, defeat enemies, and collect an Exquisite chest. Use a mechanism to open a gate, interact with a Saurian, unlock a door, and return to the Altar.

Burning Firestone #3

To obtain the third Firestone, manipulate floating isle mechanics to access a lower level of the northern isle. Follow the Little One, observe a Sentinel carry the Firestone to the southwest, and use a Qucusaurus to reach a tower. Activate a mechanism, fly to an unlocked door, use an elevator, interact with a Saurian, activate a lift, and return to the Altar.

Burning Firestone #4

The final Firestone is on the northwestern isle's upper level. Cross a bridge, use Bona to adjust its angle, glide to the upper level, lower a lift, and follow the Little One. Defeat enemies, return to the Saurian, collect a Precious chest, and head to the Altar.

Offering all four Firestones to the Altar transforms the Jade of Return into a Golden Entreaty, triggering a cutscene with the Dragon of the City of Flowing Ash. This encounter leads players to the Nursery of Nightmares island, completing The Other Side of the Sky Quest and rewarding 50 Primogems.