>>54374897>They are aliens of another planetA planet which is heavily implied to be the same Pokemon World you're from, except with Necrozma instead. Ultra Space isn't really explained properly(I mean seriously, you travel light years and somehow end up in a ruined version of Hau'oli City?) but it's sort of implied that this is a common occurrence. There's hundreds of Pokemon Worlds identical to yours with the exception of one or two major changes.
Pretty sure Ultra Space also plays a role in that one anime episode where Ash ends up in a Pokemon-less world, but I may be mistaken, and that's Ashinime anyways so non-canon as far as you're probably concerned. Just thought I'd throw that out there.
>Necrozma didnt eat their sun.Megalo Tower is literally erected because, and it is explicitly stated in game, to replace the sun that was taken in retribution after flubbing Ultra Necrozma so hard that Necrozma lost its Ultra status(described as "losing its light.")
