Had an idea. Not saying it's a good idea but an idea it is nonetheless. It goes something like this.
Instead of everyone arguing over what should and shouldn't be in every single game why not make a separate Soul Calibur or at least Soul Calibur style game devoted solely to guest characters...
Why do people think adding the word 'canon' makes whatever clearly labelled fiction they're referring to more, I don't know, 'credible'? Non-fictional? Like, say, the Bible?
Time was you could write a book, title it as a work of fiction, then go about your business as if it were ever reasonable...