>>54594286Dimensions refer to space/time. Like, the fact we see in "3 dimensions" because we see length, width and depth; and time being its own dimension. Arguably the Distorsion World is also a dimension because it's something that balances the main Pokémon world. Arguably, this is the fault of Game Freak (or maybe the translation) because they don't really separate the concept of "worlds/dimensions".
Meanwhile, by different worlds, I basically mean different universes in which things turned out differently. In this universe, there's only Kartana. In this world, there's only Guzzlord, etc. This is what Ultra Space connects, the alternative worlds in which things evolved differently.
Back to the original topic, about Eternatus, it can't be a UB because it doesn't come from a different world (which is what makes something a UB). Instead, it comes from space because it fell in Galar 20,000 years ago with a meteor. It's more akin to Kyurem and Necrozma. We don't exactly know what they are or where they come from still, but they're not UBs. If Eternatus were a UB because it comes from space, then every single space Pokémon would be a UB which is just inaccurate. Though I do agree that Eternatus aesthetically reminds me of a UB, but I find this to be a consequence of the clear inspiration from the Alien franchise.
