[Frozen]

Whoever found Tidus weak, either did not know how to use him, and never developed him either, by doing something as simple as using haste (or hastega) and then Delay Attack he can be everyone's daddy. I think he's strength relies on his excellent ability to support other characters. As for Kimarhi, I think they screwed up when they developed him, in the usage of his overdrives, since all of his abilities weren't that strong (even though they could be quite useful) I think they could have perfecly given him the option to use them as special skills, insted of having to wait to fill an entire overdrive gauge.

And hell, Yuna can be as strong as Lulu, and viceversa, if you teach them both black and white magic. There isn't really a character I would say its weak, although the one that comes to mind first is Kimhari, since I think he could have been developed better, without making him an overpowered character either.