Scratch my last. Erase, Erase. I was wrong for only going off the information presnted to everyone when I wrote the comment.
After looking further. It appears you were indeed correct about the third guy/woman whose sex is ambiguous. Lived on another world as well.
The word ‘Hometown” should have said “Homeworld” Being mixed with a lack of technology in the scene and stating he’s only interested in Jiang Yuan gives off a completely different impression of where the he/she is from. Apologies fam.
This would be easier if we could edit our comments. But it is what it is.

I went over the episode 2 times Qing(Song Yang) looks like a woman but is man according to flashback. He said his hometown not homeworld was destroyed. Flashback scene was in wushun sect. And he was sent there by the MC. It looks like he changed his appearence. But is still twisted same as before. And I think he doesn’t realise, they’re from other worlds. The only thing he is interested in MC Jiang Yuan.
If he was from another world, he would have an understanding of technology and how it works. Not once did we see anything other than magic used.

I definitely knew they weren’t from the same world. I mean when they went for a soul check in Ding’s sect, there was a little give away there when Shao yue’s subordinators were trying to reach for her leg and saying ‘why did you leave us’. I knew then she was an Immortal queen of some sort.

I didn’t even consider that they might be from different planets. You’d think watching SwS would make that obvious.

Yeah, they all come from different worlds fam. Kind of crazy really but at least we already now.

Holy crap we got their true names, and backgrounds.