Restricted Cast, who would you pick?

I think we can all agree that Terra, Locke and Celes are kinda of mandatory to the plot. The fourth character could be either Edgar or Cyan, to balance the gameplay ascpect. However, I think you would end up having to to add more skills to each character (like FFIV), because Morph, Runic and Steal are, if not useless, used pretty rarely. Now that I think about it, this is an interesting concept for a hack: less characters, but each one have an extra ability, like, maybe Locke could use Steal and Throw, Terra, Morph and Summon, etc. I don't make idea how hard it would be to code that, though. Also, changes to plot would be necessary, because, right now, I can't think anything that Cyan could specialize except for Bushido.