Junko Enoshima is a much more interesting character than I think most people give her credit for. And while I think a lot of people write her off as one-dimensional, I think that comes from a misunderstanding of how her character is supposed to work.
Junko Enoshima is a character who’s obsessed with the concept of despair. She enjoys thrusting others into despair and enjoys feeling despair herself. This makes her a good antagonist for a series like Danganronpa, because she acts as an antithesis to the message of “hope”. Though the series doesn’t always do a good job of explaining why she has this mindset,
Junko’s obsession with despair all stems from her “real” ultimate talent, the ultimate analyst. This ability allows her to quickly take in information around her, predict future events or learn new skills at a superhuman pace. Some applications of this talent included her writing a book that predicted events weeks in advance to give to her sister Mukuro in Danganronpa Zero. Copying the ultimate talents of the ultimate programmer Chihiro and the Ultimate animator Mitari. Being shown to make 1000s of predictions for potential futures in the talent development plan in V3 and so on. It’s essentially like having a brain like the characters from the series Limitless or the movie Lucy, where you can pretty much learn or do anything with minimum effort.
By all accounts, the “Ultimate analysts” ability is the overpowered standalone talent in the series. But at the same time, that potential is exactly why Junko’s so crazy.
Imagine for a second you’re so talented that you can do pretty much anything you want without fail. Without any sense of challenge, your life would get boring fast and you wouldn’t really have “fun” in a traditional sense ever again.
Imagine you’re so talented that you don’t really need to “hope” for things to work out, because you’re so OP it's basically assured you’ll succeed.
Imagine you can predict everything that’s going to happen with high accuracy, or at the very least know the most possible outcomes without fail. You know people around you better than they do and nothing takes you off guard anymore. You even know yourself so well, that you feel the need to spontaneously change your own personality.
Imagine you realize you’re far above everyone else in intelligence. It’s both alienating and frustrating as people are unable to keep up with you or see the world the way you do. Eventually, you may even grow to have a massive Ego about your abilities. But ironically people who don’t have your abilities are much happier and you resent them for it. You make them want to suffer because of it.
These are all the main points that Shaped Junko’s ideology. She’s incredibly bored, frustrated with her lot in life, alienated, and has a huge Ego. All massive ingredients for psychopathic behavior. She comes to like despair because it’s an all-consuming emotion that can distract her from that boredom and people act more erracted when placed under stress, so they’re less predictable. Heck Mukuro herself basically says this in Danganronpa Zero.
“―I don‘t know if...she is attracting despair or despair is attracting her but...she has lived her whole life with despair by her side. She lived while immersed in despair. That‘s why she began looking for despair in others. She learned to enjoy pushing people into despair. But you know, that‘s normal. It‘s the same as someone being cursed by misfortune fall into hatred for those who aren‘t. But what‘s special about her was that, she learned to enjoy inflicting despair onto
herself. That‘s how the link to despair began. As she chased down despair, she pushed it onto others on the way. Doing so, it caused her to desire falling into despair even more...and because of that chain to despair, the Super High School Level Despair was born. “
By all accounts, Junko fits into the themes of the Danganronpa series very very well. This is that talent isn’t everything, and being too fixated on your special abilities (or thinking they elevate you over others) leads to unhappiness. It’s also apt that the main hero of the series' talent is “luck” given that “luck” is one thing you can’t predict.
She even has a lot of potential for character growth given she’s technically not emotionless and does have legitimate human attachments(hence why she can feel despair in the first place). Her amnesiac self in Danganronpa Zero even shows she’ll act like a normal girl if her talent/memories are taken away, showing that her Despair state is something that was developed, not innate. She has a lot of potential to be interesting.
So what went wrong?
The main problem with Junko Enoshima is her lack of screen time combined with her poor portrayal in Danganronpa 3.
In Danganronpa 1 and 2 Junko doesn’t actually show up until the very end of the game and spends most of her time delivering exposition. You aren't really given any context on WHY she acts the way she does unless you’ve read some of the more niche side novels.
Likewise because she never really talks to any of the game casts, she never develops a relationship with any of them. Junko targeting her own sister and friends is supposed to be this really twisted form of love, but you don’t even see why she cares about them in the first place. Junko and Makoto are essentially meant to be arch nemeses, but they’ve only had like two conversations on screen. It’s like if Komeada was in one scene, rather than being built up over all of DR2.
and then Danganronpa 3 kind of just screws her stance as a credible threat. I’ve gone over this a lot in my Danganronpa 3 review, but the only thing Junko really had to prop her character up was the scare factor of “how” she ended the world. The idea that she could use her ultimate talent to orchestrate the end of the world, create a massive cult and infect the population with a toxic ideology. Her converting the cast of DR2 into her personal army was a massive gut punch that had tons of fans speculating on how she did it.
You would think it would be revealed in Danganronpa 3 that Junko’s Fashionista/Gyru persona was mostly an act and that she’s been secretly committing high-level crimes around the world while organizing a Light Yagami/Lelouch rise to power. That she used her analysis powers to zero in on the best way to destroy the lives of her followers or draw them in when they were most vulnerable.
And then it turns out the bulk of her plan was only possible because she happened to run into a character named Mitari, who happened to have brainwashing tech she could use to force people to her side. Yes, we can debate on whether brainwashing was hinted at in Zero and DR2(it was vague at best tbh), but it just doesn’t mesh well with the character. If Junko destroying the world with her “analytical power” was basically only possible because of dumb luck and a Deux ex Machina device, what’s the point?
Anyway, I would say if you want a more complex explanation of this mindset, try watching this analysis of the character Adachi from Persona 4. It hits a lot of the same points.