I would hope Yuna would be in it as both the summoner and the gunner, but I'm willing to bet it'd look something more like,

Cloud and Sephiroth (Final Fantasy VII)
Sora and Riku (Kingdom Hearts)
Lara Croft (Tomb Raider)
Whoever the main two from Dragon Quest are
Tidus and Yuna may get on there due to the FFX HD and you just know they'd find a way to throw Lightning into the mix.