What if Kris is Chara theory. Also why does Kris have the SOUL?

I know,I know Kris=Chara theories are outdated but let's think of it this way what of this is an alternate history where there was no war between humans and monsters?

In Undertale Chara is a human who went to the mountains for unhappy reasons and hated humanity, then he got adopted by Toriel and Asgore.

We don't know how long ago Kris was adopted but we do have evidence it was probably fairly sudden as Toriel took out a book about raising human children.

I don't see why Kris can't just be an alternate version of Chara, they dress the same they have a lot of parallels I think next chapter we might get a more decisive answer but I wouldnt discard it. Also Kris used to want to be a monster, maybe something to do with their hatred of humanity but could be also just a children's thing.

Also another theory of mine is that Kris has a foreign soul inserted into them for medical reasons, I believe that Kris must've had their soul absorbed by a monster maybe by the forgotten man and as a last ditch effort perhaps they inserted someone else's soul to keep Kris alive?

The intro cutscenes could've been the SOUL wich was being made for the Vessel being hijacked into Kris to keep them alive. Maybe it was some experimental attempt to create a artificial human soul?