Crono
Origin: Chrono Trigger - Super Nintendo
A Square-Enix character who first set foot on a Nintendo console, this guy is very recognizable to any who owned a SNES. He was part of a pretty popular series, which had a sequel on the Playstation. Chrono would make a great addition to the game, representing old school Square-Enix, and having various nostalgic effects on the players. He is the fighting type, and he pretty much would be a great addition to the roster. Chrono utilizes swords to fight his enemies. Chrono Trigger was an extremely popular RPG of it's time - still favorited by some gamers today. He has much potential for a moveset through his electric elemented attacks, as well as blade dances and moves. He possesses magic and swordplay at his disposal.
*sigh* Wish Square-Enix could give permission, to both him and Geno for Brawl.
On a side note, I'm just listing Chrono because he's pretty cool, not too sure where his chances stand but oh well. If it truly came down to Square-Enix representation, I see Geno, or a FF character, of course.
My most wanted third parties go Geno, Megaman, then Chrono (if Geno is not included).