MISINFOMATION. (Spoilers of hi3 hsr x story and some hsr story) Absolutely nowhere (as of now at least) in Honkai: Star rail Mentions the sky people nor A Post-Honkai Odyssey. While there are refences to characters (With welt being an exception since he is the exact same welt as Honkai impact 3rd) Honkai Impact 3rd and they share the same story. I must also mention that the Sky people you mention have no relation to what aeons (The "sky people" so mentioned) do/did to planets. (and the only hsr "mention" of kiana sleeping would be in Honkai Impact 3rd and that only exists as (loose) mention bc of the hsr x Hi3 sparkle collab)
I suggest anyone go read the page on the sky people from hi3's wiki but for brevity, none of the aeons do/did what the sky people have done to planets which is:
" The Sky People have a simple strategy for setting up an invasion: they send a Vanguard Stone to search for a planet, and if it is suitable they send its coordinates to their home-world for reference." (the closest" you can get here is nanook and that's stretch since none of their minions or them do anything close to that) and if all of this was true how would you explain The Sugars? Where are they? They are part of the sky people after all. I deeply appreciate the guides and walkthroughs (Thank you) but this is bad given the playerbase refuse to read.