The domains.
The Upper Domain, or Higher Domain, is a domain that forms the other half of the universe, with the Lower Domain being the other half. It is where U-DO exists, and from where it observes humanity.
The makeup of the Upper Domain, such as whether it has a similar two part system as the Lower Domain, as well as the concept of 'space' and 'time', is impossible for anyone to perceive from the Lower Domain.
Despite this difference in structure, the Upper Domain is intimately linked to the Lower Domain, as two differently constructed halves of the same whole. As such, if one domain or the other becomes dysfunctional or collapses, the other will be just as affected.
Access[]
Normally, the Upper Domain cannot be perceived or accessed by anyone on the Lower Domain. It is only through the act of U-DO accessing the Lower Domain, in order to observe humanity, that humanity is able to gain access back to it.
It is also through that contact that humanity is able to access the power coming from U-DO itself, enabling phenomena long thought impossible in the Lower Domain. With such power came consequences, such as the threat of a matter shift.
Usually access is made through things such as the Zohar (and later, the Zohar Emulators), but there are rare people are are able to draw out this power without using an artifical system, such as Shion Uzuki's mother, Aoi Uzuki.
While others exist on the Upper Domain, since only U-DO has accessed the Lower Domain, only U-DO's existence is known.[1]
- ↑ Perfect Guide. "01. What Kind of Connection is There Between the Upper and Lower Domains?"