The Final Fantasy series has always done a pretty decent job of catering to a wide variety of playstyles. In the early days, this was accomplished through the ever-expanding job system, which effectively allowed players to change the class of each playable character to gain access to new spells and techniques. In later installments, however, developers simply increased the number of potential party members, which, for the most part, allowed players to select the three who best catered to their own specific needs.
As a result, it's not always easy to rank party members based solely on their performance in battle, as one player's hero can be another player's zero. That said, there are certain characters who are widely considered to have failed to live up to their status in the series' lore; either due to their awkward abilities or their subpar stats. These underwhelming Final Fantasy characters are strong in lore, but incredibly weak when it comes to combat.
Quistis Trepe (Final Fantasy VIII)
As a child prodigy and one of the instructors at Balamb Garden Quistis has a lot going for her at first glance. Things don't start out too badly for her either, with Quistis more than capable of holding her own during the early stages of Final Fantasy VIII. Unfortunately, however, while other party members grow stronger and stronger as they level up, Quistis kind of just stagnates and becomes increasingly difficult to use effectively.
This is because her blue mage abilities are tied to her limit breaks, which makes them far more situational than they already were. To further complicate matters, the strength of her spells and abilities is affected by her Crisis Level much more than other characters in the game. To her credit, she can actually be pretty useful for farming and level grinding as a result, but, when it comes to dishing out damage, she's outclassed on multiple fronts.
Vincent Valentine (Final Fantasy VII)
There are several weak party members in the original release of Final Fantasy VII, with Yuffie and Cait Sith probably the biggest offenders of them all. The thing is though, a thief and a remote-controlled stuffed toy cat being weak in combat shouldn't really come as too much of a surprise to players. The same cannot be said, however, when it comes to the immortal chaos-infused badass that is Vincent Valentine.
He may be one of the coolest party members in the history of the franchise, but he falls some way short when it comes to living up to his reputation in battle. His limit breaks are some of the worst in the game due to the way that players lose control of him and his ultimate weapon is incredibly frustrating too. It does actually have the potential to be the best one in the game, but the amount of grinding required means that most players will give up on Vincent long before he ever becomes viable; assuming, that is, that they even bother to recruit him in the first place.
Tellah (Final Fantasy IV)
Tellah may be old, but he's still considered to be one of the most powerful mages in the world of Final Fantasy IV; at least when it comes to lore, anyway. In reality, the Great Sage has forgotten how to cast most of his spells, making him no better than any of the other magic-using party members in the game. In fact, due to his MP capping out at just 90, he can be pretty atrocious during longer fights and actually gets worse as the game goes on. This is because, unlike other characters, all of his stats bar HP decrease as he levels up.
Perhaps had Tellah been alive for centuries this little detail might have made sense, but he's only actually 60 years old in the game. Granted, he's still no spring chicken, but he's not exactly knocking on death's door either. At least not to begin with, anyway. Eventually, Tellah does actually remember his most powerful spells and vows to use Meteor to put a stop to Golbez. Unfortunately, however, the strain of casting the spell kills Tellah, yet Golbez lives through the attack to fight another day.
Gau (Final Fantasy VI)
Gau is a feral teenager who grew up on the Veldt; a near-endless plane that powerful monsters from all over the world of Final Fantasy VI are said to gravitate towards. To have survived in such a place for thirteen years, players would be forgiven for thinking that Gau is incredibly strong and though he's certainly presented this way throughout the events of the game, his lackluster performances in battle paint a very different picture of the green-haired Gestahlian.
Though his ability to learn enemy skills and imitate the elemental affinities and resistances of his foes sounds good on paper, it ends up being petty mediocre when put into practice. Most of the skills that he can learn are pretty useless and those that aren't are difficult to learn and quickly outclassed once players start to get their hands on some of the more powerful Magicite. His inability to equip weapons doesn't help his poor damage potential either, nor does the way in which he's controlled by players.
Kimahri Ronso (Final Fantasy X)
Like most of the other blue mages in the series, Kimahri is a little lackluster when compared to some of the other party members found in Final Fantasy X. This probably wouldn't be such a big deal were it not for the fact that a fairly sizeable chunk of the game's narrative is spent reinforcing the false notion that Kimahri is incredibly strong. It's hinted at a lot by the way that he carries himself too, but not nearly as much as it is through his redemption fight.
When players arrive at Mt. Gagazet, they're forced into a two on one battle with Biran and Yenke; two of the other Ronso who have bullied Kimahri for much of his life. Unfortunately, however, most players tend to avoid using Kimahri due to his lack of a clearly defined sphere grid route, meaning that he's often under-leveled and lacking the skills and abilities heading into the fight. As a result, it can be a pretty frustrating battle despite the best efforts of the developers and is a big part of the reason why Kimahri is so unpopular with so many series fans.