Yu Yevon will make a surprise appearance.The fans will naturally go what, but be unexpectedly pleased by his actual portrayal in the game, making him more than a joke and a disappointment in the eyes of fans. Bonus points if Square-Enix keeps his "tick with a glowing eye" form.
The game is gonna be part of an Alternate Continuity.Self-explanatory, really, considering the game's art style and premisenote , but there's still the question about how this game came to be. So, my guess is that this game spun off from a custom quest (read: playable fanfic) from Dissidia 012 Final Fantasy, since that game's Japanese version allowed people to share their quests online via Mognet: one where a villain, most presumably Kefka, got reality-warping powers from Chaos and used them to turn the heroes into their avatar versions, as the game's quest editor allows players to include them into their speech bubbles. Square found out about that quest, went "Sure, Why Not?" and the rest is history. Or this game simply makes all of the heroes' avatar versions seen among the avatars in Dissidia 012 an Ascended Extra. Either way, this is the theory.
Three heroes, one villain. Each game will be represented by those numbers, in order to avoid the fandom backlash Dissidia 012 experienced after VII got three heroes (only Cloud and Tifa were actually playable, but Aerith counts anyway, and of course Sephiroth was the villain) whereas some slightly less base-breaky games got diddly-squat (all VI and IX got where additional stages, both of which were the smallest in the game)...or is this too much wishful thinking?
The exclusive characters for Theatrhythm were originally planned for Dissidia but got cut out. They just couldn't figure out how to make ol' man Cid fight.