The Final World

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

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 "someone". 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".