As everybody was talking about Bravery Default's Agnes in the very previous articles (which I apologize to bringing up such subject again), I do disagree that she'll join the Smash team. Yes, she may be popular and her abilities may fit in Smash, but imo, Bravery Default is still minor in franchising. I may be wrong which I'm aware, but I doubt there are people mentioning her to SSB4 at all.
In my opinion, if you're gonna choose a character from Square Enix, it gotta be a game which is the main face of SE, which is Final Fantasy series. Yes, BD have a classical Final Fantasy element in it, but using the original FF seems understandable rather than any spin-offs. But there are so many characters in Final Fantasy to choose from, so which to choose? FF protagonists may be a best choice but it have to be one of the main protagonists from their own series, like the first version is Warrior of Light, and III is the Onion Knight. FF1~6 can be chosen since these sequels were sold for Nintendo back then, and we know we can't choose the series after 7 such as Cloud and Tidas because their series were later thrown to PS (which this also made Nintendo and SquareEnix's relationship break apart). If not them, maybe mascot-ish FF characters can be good, which is Moogle, Chocobo, Black Mage, etc. Moogles look kinda weaker than Jiggs and Black Mage doesn't appear in every FF series, so maybe Chocobo can be the most fitful character in Smash. Not as being a Yoshi clone, but can use magic like he did in his own dungeon game series. His final smash may be a problem, but how about summoning other Chocobos and attacking everybody like crazy...like those Cuccos do. (lol)
There is Dragon Quest on the side but this game isn't really that famous in the foreign since it was released really later than FF, but since their mascot character is the common enemy Slime, maybe he can join along with Chocobo and fight with him, like that Duck Hunt Dog. Secret of Mana series can be a good choice since they're moves are fitful to Smash and released a lot in Nintendo, but probably difficult since the series are stopped since the 4th sequal, and people hardly mention about the game since then, which is the sad thing. Kingdom Hearts will be extremely difficult to offer such crossover battle in Smash because KH also belongs to Disney, which is very strict when it comes with copyrights and it'll cost a lot of money, so sorry KH fans but Sora ain't gonna make it.
If I were to choose the two anime Mewtwo, I'd choose the left one. I don't know, but he look kinda cute for some reasons. (lol)