The Final World

The Final World is an original world in Kingdom Hearts III.

Settings and Areas
The Final World is a type of limbo realm that awaits all who lose both body and heart, but still retain their will and a powerful attachment to the realm of the living—hence its name of "Final World", as it is the last world most who visit it will ever see. For those who still manage to hold onto their heart and body despite appearing in the Final World, it is still possible for them to return to the land of the living. For Sora, he needed to collect one hundred and one broken pieces of his body, while for Chirithy, it was the promise of a reunion with his Keyblade wielder, Ventus. All others eventually lose their appearance and identity and take the shape of a star, their minds being put at ease while simultaneously retaining the parts of their memories that long for their old lives.

The Final World mostly consists of an infinite sea and sky. Deeper into the realm lies a labyrinth that consists of a multitude of crystalline cubes and pillars, suspended in the sky. By striking the glowing cubes it is possible to twist and turn the structure.

According to Chirithy, The Final World is nested closely to the Station of Awakening and the realm of sleep. Those who sleep or visit the Station have a chance to catch a glimpse of The Final World, as Sora does when he begins his journey.

Kingdom Hearts III
When Sora began his Dive to The Heart, he fought a transparent, glass-like Darkside

After Sora, Donald, Goofy, Riku, Kairi, Aqua, Ventus, and Mickey were consumed by a Tornado of Heartless, Sora ends up in a flat reflective plane, similar of the one he was at when fighting the Darkside at the Station of Awakening. After wandering thru the area, a light came down, revealing itself to be Chirithy. Surprised as to why Sora still has a psychical form, although transparent, it states that Sora and his friends were being tethered, thanks to the help of Kairi. Chirithy states that sora needed to collect the "pieces" of his body, in the form of him walking around and doing other actions. After collecting the first ten, a teleport to a labyrinth appears, alongside nameless stars, of those who have been left without a body.

Sora then meets one notable nameless star, who says they were stripped of everything but their heart, as they wait for someone whose has been changed beyong reconization, "his heart changed for another's". Sora infers that it could be a Nobody, but the stars says it was a "Somebody". Sora asks for their name, who the nameless star whispers to him.

After completing the rest of his body, completing himself, Sora then asks why Chirithy is there, who says that they are waiting for "Ventus". Sora then asks how to save his friends, and is answered by a snarky remark at not knowing how to "restore people's hearts". Sora, figuring that it's the "Power of Waking", decides to try and use it to rescue his friends, as Chirithy instructs him to "Look for the light in the darkness".