Dissidia Final Fantasy (2008) characters

Dissidia Final Fantasy features one hero and one villain from the first ten main Final Fantasy series, plus one special character each from Final Fantasy XI and Final Fantasy XII.

Cameo characters outside the in-game storyline
There are many other cameo characters (hailing from Final Fantasies I through XII) outside of the in-game storyline, all of which speak directly to the player, usually guiding them through information, tutoring, and commentary.