I’m doing this off the top of my head, and mostly from some rather old and sketchy memories, so please forgive me if I’m a little disorganized or not 100% accurate. Still, I’ll give it my best shot!

Misawa is basically that kid who was probably at the top of his class back at his old middle school. He was the gifted kid everything came easily to, and he expected that this state of affairs would continue when he got to Academy Island. He thought he was going to walk in and do his thing, everyone would be very impressed with him, and he wouldn’t really have to do anything much or exert himself particularly. Only it didn’t happen that way, because Duel Academia is where the kids who are gifted in dueling go, and half the people he comes into contact with are also really, really good at stuff. Suddenly he’s not having it all his own way anymore. He’s having to compete for attention with genuine showstoppers like Juudai and Manjoume, who aren’t just good but also personable and exciting. Even on those occasions when Misawa wins, he just isn’t as interesting as these other guys, and the more time passes, the more he finds himself overshadowed.

Of particular note is his interaction with Taniya, which I think a lot of people get wrong. It’s so easy to read Misawa’s character as “he cares too much about science and logic, and he needs to be more in touch with his emotions!” Being too logical is never Misawa’s problem. His problem is that he wants to be logical and his emotions overrule him. That’s why he loses and continues to lose to Taniya. She’s a very passionate person, but she can also be calm and logical when the situation calls for it, and when they first meet, Misawa hasn’t got that kind of balance. The minute she starts appealing to his heart instead of his head, he comes unglued.

So the season two and the Society of Light comes along, and his life is starting to unravel, because here is where his personality flaws are really starting to bite him. Right from the start, we’ve seen that he’s a guy who thinks he has it all and doesn’t need to change. The first time he meets Juudai, they banter over which of them is going to be number one in the school, with the strong implication that Misawa thinks it’s going to be him. When everyone goes rushing off to look at the shipment of rare cards (the one Chronos takes for Manjoume, as it turns out), Misawa says he doesn’t need to worry about them because his decks are already perfect. Even when he loses the key he’s supposed to be protecting, he comes off as more concerned about what went down between him and Taniya than the fate of the universe.

We tend to treat him as a part of the friend group, but we rarely see him hanging out with the others as friends. When he hangs out with the group, it’s because he wants something from them, whether it’s getting them to help him repaint his room when he expects to be promoted, or whether he’s just enjoying lording over them to “train” them during the Seven Stars arc. He doesn’t hang out with them just for the fun of it.

And the other characters notice this. I really think the whole reason Sho starts in on the whole “Oh, are you here?” routine is because basically, Misawa doesn’t make an effort to hang out with the gang most of the time. It’s less of a “you are unimportant to us” thing and more a “look who decided to grace us with his presence!” thing. He took it for granted that his friends would be there when he wanted them, so he didn’t make much of an effort to keep in touch with them, and then when he did finally realize he wanted them around, the damage was already done.

And then the Society of Light swoops in. Saiou played Misawa better than he played that piano of his. He saw how much Misawa cared about his reputation, he saw how he was starting to realize that he was being overshadowed by the flashier and more charismatic duelists, and he realized that there was no reason he needed to try to recruit Misawa when it was clear Misawa would come to him given enough time. Misawa wanted a fast track to being admired without having to put in the actual effort, and Saiou promised him exactly that. (Pay close attention to Misawa’s vision just before he throws the duel with Manjoume, and you’ll see that his imagination is populating the Society with swarms of cute girls ready to welcome him into the fold - those pesky emotions overruling logic again!) So he joins the Society.

And doesn’t enjoy it because it still doesn’t get him what he wants. Finally, Zweinstein shows up, and his duel with Juudai makes Misawa finally confront the idea that he needs to work on himself. So he goes off on a journey to find himself and drops out of the plot for a bit, which is unfortunate for his characterization but it’s what we’ve got.

But when he comes back, there are subtle signs that he’s a changed man. The first thing he says when he sees the transported Academy is not “come and save me” but “don’t come here, it’s dangerous!” Later, we see him making every effort to save the others and get them home safely, without showing any signs of wanting to be hailed as a hero for it. When Juudai sets out to rescue Johan, Misawa comes along even though he believes the chances of surviving are infinitesimally small, because that’s his friend and he needs to help him. They’re little things, mostly, but they demonstrate that he’s finally stopped letting his ego rule his actions and started caring more about other people.

And so he gets his reward. He’s one of the few people to survive the Dark World arc without anything tragic happening to him, he re-unites with the woman he loves and helps her save her people, and presumably he gets to live happily ever after, which is better than some of the cast gets.

You might treat him as a foil for Marufuji Ryo, who also suffered from “gifted kid” syndrome. Both of them had a meltdown when they finally ran up against people who were better than they were and broke their illusions of themselves as “perfect”. Their main difference is that Misawa went looking outside himself for reassurance and got sucked into the Society of Light, whereas Ryo turned inwards, rejecting everyone around him and devoting himself solely to building himself up.

So anyway, that’s my analysis of Misawa. I know it’s not the mainstream opinion, but I hope it at least gives you a starting point for further consideration.

…Yeah, I think you pretty much nailed it! 

I’ve picked up on a lot of this as I’ve re-gone through episodes, especially his tendency to focus on logic over his emotions (which you addressed very well, and which definitely comes into play with Tanya), but you put it all together really well. :) 

Definitely onto something with his concern over his reputation (which gets highlighted in 82 as Manjoume and all the converted White students laugh at him calling himself Ra’s “top student,” with a classmate even saying, “you’re hyping yourself up!”) And yeah, that part about his not really hanging out with the group as a friend I think has some merit to it.  Even in 82, he really only ends up with the group initially because of his inner turmoil about the Society of Light and whether the group feels anxious over potentially joining them with half the school converted (to which Judai basically says “we always have and always will be Reds”).  I do think he does hang out decently with the others (their getting together to watch Ryou duel Ed, for example), but I think there’s something there, and with putting the “Oh, you’re here” thing in the lens of his usually wanting something out of the interaction which does feel accurate, so I think you’re right in how after his time with Zweinstein later, his mindset has shifted and he’s selflessly trying to help them get back home–it does feel different from the slightly smug, “my deck’s perfect,” Misawa we have initially.  When that “Eureka!” hit, it definitely really hit.

And I suppose it does speak to our human need for validation, too, in the way he looks outside himself to Saiou and the SoL for it only to learn the lesson that it comes from within.  I think it’s realistic that he’d go off for a while and do the work to improve himself, and he does ultimately come back stronger for it.  Also like the nod to the other extreme that happened with Ryou and his closing himself off to focus only on winning, respecting opponents be damned.