Multiverse Terra Theory
So this is like half theory half guessing, but I think I've figured some things out about the characters and what "Terras" (as they call them in the lore) they come from. I've always been under the impression that most, if not all, characters came from different terras. The only real exceptions up to this point were the Yamaokas and then Blight, Felix, Twins, and Elodie. However, after watching a video on youtube by... I forget who (I'll look it up later, it was a good video) about the characters and how they were connected, it got me thinking. Are all the original characters from the same terra?
Here's my thoughts. No. I have no reason to believe all original characters are from the same terra. Instead, I believe characters from the same chapter come from the same terra (and if there's a tie between multiple chapters such as the connection between Felix and Elodie, it means all related chapters come from the same Terra). I also believe if two killers share a realm they come from the same terra. To me, it makes sense that, if the entity was going to change up certain places and put them in new locations, they'd be in a place that has already been taken from the same terra. Maybe that might be putting a lot of faith in the entity to not just be like "Let's place mix and match," but that just feels realistic.
Now to keep things simple I'm just going to letter of Terras instead of trying to name them because we don't know what the names of each characters Terra is.
Terra A: Trapper, Wraith, Hillbilly, Dwight, Meg, Claudette, and Jake
Terra B: Nurse, Clown, Nea, and Kate
Terra C: Michael Myers and Laurie
Terra D: Hag and Ace
Terra E: Bill
Terra F: Doctor and Feng
Terra G: Huntress, Plague, David, and Jane
Terra H: Bubba
Terra I: Freddy and Quentin
Terra J: Pig and Tapp
Terra K: Spirit, Oni, Adam, and Yui
Terra L: Legion and Jeff
Terra M: Ash
Terra N: Ghost Face
Terra O: Demogorgon, Nancy, Steve, Jonathan
Terra P: Deathslinger and Zarina
Terra Q: Pyramid Head, Cheryl, James, Cybil, and Lisa
Terra R: Blight, Twins, Artist, Felix, Elodie, and Jonah
Terra S: Trickster and Yun-Jin
Terra T: Nemesis, Jill, Leon, Claire, and Chris
Terra U: Pinhead and Chatterer
Terra V: Mikaela
Most of these given the rules I gave I shouldn't have to explain. However I'm going to explain a few in particular. First off, Terra K and S. I'm sure many know by now, especially if you read cosmetic descriptions or saw the same video as I did, know that Adam's cosmetic that came with Seoul Sights mentioned him taking his students to see a Trickster concert. However I didn't include Trickster and Yun-Jin as a part of Terra K because we know that cosmetics are not canon. As you may have noticed, I only included legendary skins for licensed characters because they'd obviously be same universe, we've seen/played their shows and games.
The other one I want to explain is Terra R. You might have noticed I put Artist and Jonah with our good friends the Pariahs and their respective killers. The reason I did that is because Artist and Elodie both had an encounter with the Black Vale and as of this point, we have no confirmation that they are a multi-terra organization. So to keep things simple, anyone I noticed had a connection to the Black Vale were put in the same Terra.
Anyways, that's my theory about the terras and which characters are from the same terra. Were there any characters with a connection I missed? I'm curious.