No no no. Fictive is specific character. Fictionkin is fictional species. Omg.

I have never heard these terms used this way before. Is there anyone who also uses them this way?

When we on livejournal started to use the term ‘fictionkin’ as a replacement for ‘otakukin’ it was to mean anyone from a fictional universe, specific character or not. I acknowledge the meaning may have drifted a bit, but I have never heard it used in such a way as to disinclude people who were specific characters.