Universe Alpha (shortened to UA or Uni-Alpha) is the progenitor to all known universes in existence in the Multiverse -- with many attesting Universe Alpha to be the first Universe to ever exist in the entirety of the Omniverse. The theory for Universe Alpha arose from many universes initiated contact and finding fifth- and sixth- dimensional similarities, including possessing similar species to humans, similar advancements in technology, similar religions, and similar histories. A prime example of this is the contact between the Third Reich in their 1945, and the Eternal Reich in their 2050.
Universe Alpha is speculated to harbor the original Humans; or at least, the ancestors to the Humans. It is also speculated to be unalterable and untamperable through any means of space-time-planar manipulation, to ensure the spatial and temporal purity of Universe Alpha. This inability to meddle with Universe Alpha is commonly used as a rapport for theism, as only a higher being can intelligently and omnisciently deny any and all access attempts to Universe Alpha.