Multiversal cluster
A multiversal cluster, sometimes called simply a multiverse or quantum multiverse, was a grouping of universes within the wider Multiverse.
Universes within a multiversal cluster often had a causal relationship, branching out of each other; for example, the multiversal cluster surrounding the universe of the Endless all fell within the purview of Destiny of the Endless. (PROSE: Psychopomp) Doctor Sigma once explained that if a limited “quantum multiverse”, comprising the timelines splitting off from a given source universe, was a tree, then the “true” Multiverse, what “some pompous folks” called the Omniverse, was the forest containing all possible trees. While given universes and quantum-multiverses might follow specific sets of physical laws, such as quantum physics, all possible worlds were represented across the scope of the Multiverse, including ones running on Newtonian physics or purely magical principles. (COMIC: The Beginner's Guide to Multiversal Theory)
The modern Master of the Strange and Wonderful House had “memories the size of a million eternally propagating multiverses”, describing himself as being “on the infinity kick” when he occupied his function as Lord of the Manor. (PROSE: Our Strange and Wonderful House: The Will of the Creator)