What happens when you need to decide just how a character sees the world, and how they behave in it? All sorts of graphs and charts and other systems can measure your personality, such as the famed Myers-Briggs types to the moral alignment chart of Dungeons & Dragons. That chart is meant for player characters in that tabletop game, but it can be used to measure characters in anime, too. Why not try it on My Hero Academia?
For those not familiar with it, the chart goes like this: Good, Neutral, and Evil on one axis, and Lawful, Neutral, and Chaotic on the other. That makes for nine combinations in a 3x3 grid (and Neutral Neutral is really called True Neutral). Most of the heroes and students in My Hero Academia are good guys by default, so let's consider "neutral" in relative terms so we can fill out that chart. Some of these heroes are more idealistic than others, after all. Some just want to get the job done or prove someone wrong.
9 Lawful good: Tenya Iida
Really, how could it not be him? Tenya Iida, or Ingenium, is the class president of hero class 1-A, and he takes the role seriously. This young man follows the rules to a T, scolds silly or lazy behavior, and gets good grades while upholding the honor and ethics code of heroes.
Iida also volunteers as a coach for the other students, like when the boys all hung out at the campus pool and Iida trained them a bit. The only exception to this is when he ran off to confront Stain and avenge his brother's defeat.
8 Neutral Good: Izuku Midoriya
Hero alias: Deku. Izuku is a highly idealistic boy, and he yearns more than anything to save everyone from evil and be a symbol of peace. That dream may be realized now that All Might gifted him with One For All, the superpower quirk! Izuku is a good guy to a fault, but he's not especially "by the book" or rogueish about it. He strikes even, with his tactical mind and strong ethics on one side and his willingness to leap into danger on the other.
Izuku helped lead the rogue hero team to rescue Bakugo from the League of Villains hideout, after all, but did not complain when he got scolded later.
7 Chaotic good: Inasa Yoarashi
What's up with this guy? He eagerly wants to be a hero and save the day, and he learned to get along with his enemy, Shoto Todoroki. But you never know what he'll do next. This boy loves passion, and he wanted to enroll at UA. During the entrance exams, though, Shoto refused to acknowledge him, and Inasa took it very badly. He rashly quit and enrolled at Shiketsu instead.
He also yells happily and goes way overboard to apologize, and he fought all on his own to knock out 120 opponents in the hero license test! His passion takes him all over the place.
6 Lawful neutral: Inko Midoriya
She's none other than Izuku's mom, and what a doting parent she is. All by herself, she raised Izuku into a fine boy, and it seems she took few risks when it came to her parenting. She also has a strong sense of responsibility and took it very hard when her son was diagnosed as quirkless.
Later on, Inko was quite worried about the kind of danger Izuku was facing during his training, and very nearly pulled him out of hero training altogether. She, All Might, and Izuku talked it out, and really, we can't blame Inko for being so concerned. Imagine your darling boy coming home with broken arms!
5 True neutral: Shoto Todoroki
He and Momo are the two UA students of class 1-A who got into the school through recommendations, and this boy is wildly talented. But while he takes hero training seriously, he's not really idealistic, but rather selfish. Shoto is desperate to get out of his father's clutches and forge his own path, and he'll coldly go through any obstacle to do it.
Overall, Shoto pretty much toes the line as a student, though he did take part in the rescue mission to retrieve Bakugo. And to his credit, he's slowly warming up to his classmates, which they appreciate.
4 Chaotic neutral: Katsuki Bakugo
King Explosion Murder! Okay, not really. Consider his hero name a WIP. Anyway, Bakugo is easily the hothead of class 1-A in more ways than one, and he's just as selfish as Shoto is, and more of a wild child about it. He desperately wants to reach great heights like All Might, and he can't stand the idea of the formerly quirkless Izuku getting ahead of him like this!
It's brutal on Bakugo's pride and self-confidence, and he lashes out by challenging Izuku to a serious duel! He's horribly uncooperative and impulsive in battle, but fortunately, his instincts and sheer power see him through most situations.
3 Lawful evil: Overhaul
Viewers of the anime haven't seen as much of Overhaul as the manga readers have, but we've already got a solid impression on him. As his costume suggests, he's meticulous and loves clean spaces, and will complain about dirt. That suits his personality, too, being the son of a yakuza boss. In this world, the yakuza has to tread carefully and discreetly to survive, and this made Overhaul a practical and cunning criminal.
Overhaul also scorns Shigaraki's sloppy leadership and assumes command of the League of Villains at once. Izuku's new arch-nemesis has arrived!
2 Neutral evil: Kurogiri
This mysterious villain isn't much of a fighter, and his quirk makes teleport gates. He treads the middle path where villainy is concerned, since he is not the mastermind but neither is he an impulsive rogue or brute. In fact, he's kind of a parental figure among the villains, keeping the gang cohesive. That's helpful, but he's no leader.
Instead, Kurogiri makes for an excellent support figure, allowing his allies to raid anywhere and retreat just as quickly.
1 Chaotic evil: Himiko Toga
This girl is actually only a C-ranked villain, but that's just on paper. In practice, she's an acrobat with a tricky quirk, and her schoolgirl uniform is loaded with gear. Himiko was a loose rogue who joined the League of Villains so that she could emulate her hero, Stain, on a rampage.
Himiko primarily operates alone, and she even infiltrated the hero license exam arc by taking the place of the Shiketsu student Camie. And she's bound to have more tricks up her sleeve in the future!