Hmm, okay.

Squall from FF8- Hell, as Xanatos already said, his limits break asses for fun and he can take on the roles of many. Meaning he can be a mage for a battle, a support character, a tank, or the beast.

Lulu from FFX- She is sexy more over everything else. But yes, her attacks are awesome. Doublecast, single mp, ultima for the win, also, ultima whirl can do damage.

Vanille from FF13- I'm one of the only people who dislikes FF4, so the other white mages seemed... not right. Plus, she saved my ass sooo many times... Even if I do have to turn down the volume, because she makes explicit noises when struck >.>

Bartz from FF5- Again, I can interchange class at will. He can be a sage, or simply mime squalls Lionheart.

GoGo FF6- Same here with the interchanging. I can again mime Squalls Lionheart.

And finally, Fang from FF13- I wasn't sure who to chose, but I needed more sexah in my post, plus she is strong and can be a pretty good tank.

Battle tactic?

Have squall cast meltdown on enemy, have Bartz cast Haste on Squall, Have GoGo use item, Aura on Squall.
Squall use Renzokuken, and hopefully a lionheart, Bartz and GoGo follows, doing massive damage.