Aah, character things... I wanna join iiiin~
Bennett - Honestly, I have this hypothesis that one problem with Bennett is that he is kind of used to having people give him what he wants.
We know that Serra gave up a lot of things so she could take care of her son. She tells us as much, and it's obvious that it was a huge personal sacrifice. She put Bennett above everything, even if it clearly makes her life less satisfying.
And El apparently handed him the E4 job, and even though he says it's because he saw the boy's battling prowess, that just seems like an excuse. But point is, Bennett gets his dream of joining the league leaders pretty much handed without the effort that it should probably take him (it doesn't even look like he and Laura had to hold any sorts of tests to compare who is more fit for the position. Since Laura gets her news of being kicked quite sudden and without any warning.).
I feel like he is, in a way, spoiled, and has difficulties accepting that Luna can't / doesn't want to give him exactly what he wants from her. They might have been friends of some sorts when Luna stayed with Serra, who knows. But Luna doesn't want anything more, and Bennett probably has difficulties with letting that get through to him. But I think Monochrome_Complex put it pretty well with the word "Metamorphosis". I think he's gonna get character development for the better.
Fern - I thought I'd hate this guy. After the comments he made about Corey, I really thought I'd hate him. But somehow I don't. Let's face it, he's a jerk, but he's also so desperate. If anything, then his interactions with other characters (mainly Florinia, but also a bit Solaris) in E15 show that he's cracking.
I'll stick to my hypothesis that Fern has always been feeling greatly underappreciated and frustrated.
First of all, he's always just second-best (at best). He's overshadowed by his sister, who gets to be gym leader while he is "only" the reserve. Then he starts the league challenge, only to find you always at roughly the same level of progress, and always, always beating him. You simply are the better trainer.
Really, everything about the way Fern presents himself screams "Pay attention to me!". Perhaps he doesn't even mind if it's negative attention. He just wants people to give it to him.
Speaking of the PC being better than him - his response to Solaris commenting on your talent? "It's not all about [x], you know?"
He's gone and joined Team Meteor, and he's on his presumably first important mission with them - and then he fails to win against you again, and his boss pays all the attention and compliments (as far as Solaris compliments his enemies, anyway) to you. Feels bad, man.
And then there's the stuff that supposedly happened at Onyx, the whole story about Florinia and Titania and the things that made Rini the way she is. He claims he doesn't care, but really? I think it must have affected him more than he's willing to admit.
I think Fern's character development part is due very soon.
Sigmund - Oh I love that guy. Yes, he's got questionable morality and clearly, he's not a responsible therapist/doctor. But a real bad guy? Nah. He's said as much - he is working with Meteor because he wants to figure something out. I guess it's safe to say he's still trying to work out the truth behind Lin. I mean, we know that Sigmund and Saphira recognize her. I'll be damned if Sigmund isn't staying with Meteor for the sole purpose of understanding what's going on with that leader of theirs. And I kinda feel like we might have more of an ally in him than we're supposed to think (or want). He already told us he thinks Meteor's goals and methods aren't to his taste. He has his own little agenda.
Titania - I feel like I'm supposed to like her. Or at least supposed to think that she's cool or anything. But nah, I don't. I do like that characters like her or Saphira give us a taste of "not everyone who is on your side is a good person" and "war is brutal" or something. Not everyone is nice and friendly and respects their enemies. But there's really barely anything that makes Titania a likable character to me. There were a couple of brief moments that I liked in E15 - I liked it when she gave Taka a piece of her mind on his unwillingness to make a clear stand on his loyalty. The part where she basically tells him that someone in his position needs to "man up" and make up his mind, instead of letting others dictate his actions. I liked their interactions because Taka also gave us some great lines directed at Titania. Their exchanges were meaningful and made reasonable points.
But other than that, I don't like anything about the was Tania interacts with others, including you. And unlike with characters such as Fern or Bennett, I don't really get the feeling that she's gonna have any sort of revelation about her actions, or change her ways. Her personality as a cold and condescending person who cares about nothing besides herself and Amaria feels set in stone.
I suppose we'll get backstory eventually, seeing how it's all mixed up with the stories of Rini, Amy, Fern and Julia. But even if she gets a solid backstory to explain her current personality, that doesn't exclude her from needing some serious character development. If she's a main character (and I count the leaders as main characters), she shouldn't be static.