- "The day sky had turned a dark blue, its horizons of a lighter tone. And beyond the silver clouds were countless bright stars, dotting the altered firmament. Yet these stars were not stars, but the million eyes of a million things turned towards the small blue planet, waiting in unknowable eagerness for the rebirth of one of their kin."
- ―Harry's thoughts on the Celestials.
Celesial is the name given to a group of extra-terrestrial entities known to dwell in the cosmos and beyond it. The nature of these beings is mostly unknown to humans, but some came to be worshipped as deities because of their great power. One of these would be Reo, whose corpse was found in a beach of Caligon and came to be venerated by the blood-worshipping inhabitants of the isles.
Although physically mortal, the Celestials seem to possess some sort of spiritual immortality. In Reo's case, his fatuous essence lived on through his blood, which later allowed him to be reborn through a human with Celestial blood. In this example, the resulting rebirth did not possess Reo's pre-mortem personality, instead being shaped by the mind of its human forbearer. In this state, the very essence of a Celestial was enough to tear an entire archipelago and drag it into a dreamscape, as well as to call the dreaming minds of those that had Celestial blood in their veins, in order to seek a proper vessel for rebirth.
- Dreams of Blood (First appearance)