It's over 8,000!
Not sure if this is correct but I got the impression that most final forms actually makes their debut in the movie (I know this is true for sure for Agito at least), but western fandoms don't feel that because we only get to watch the movie wayyy later. Not sure if this is true for Faiz, but I think it is because his debut in the movie is way flashier, just like Agito
I believe Shining Form debuted in the special. The special was still part of the series.
I think Blaster Form did in fact appear in the movie before the series, but since they're debuted in different places and in different stories, they both count.