Your personal Tumblr journey starts here
"Source trauma" and "exo trauma" is real btw.
You can have trauma from something that didn't actually happen because trauma is a reaction to a distressing event, regardless of the actual event happened. Both are comparable to real trauma, so for the love of god stop acting like introjects can't be traumatized from source.
Fictional introjects can be IN their source, they can come from their source. They are no different from other alters.
They can have real experiences as being that character because they're can be that character and if they genuinely believe they do/are, that's not a bad thing and whether source separation is needed, the alter will come to their own conclusion some day.