Also, besides all that, right at the beginning at like, that first test where Niro's shoes were ruined, he said something about Evan already knowing that the test would be impossible without shoes, and sabotaging him on purpose. I feel like this ties in nicely with your theory that the headmistress is kinda iffy and that Evan has something to do with it
Oooh, that's good! I forgot about that detail~(๑•ㅂ•)و✧
I'm not really familiar with it, but is that a reference to the joke that gingers don't have souls?
I've binge read all the chapters released so far (1-25), and I gotta say that I'm a little suspicious of the headmistress of the academy.
Potential Minor Spoilers Ahead:
So I don't know if anyone caught it, but in one of the recent chapters (somewhere in 24 when they're learning that Arphonia spell) there's a panel where a woman with red hair (a little wavy) and maybe dark lipstick (maybe just lighting for that bit) is shown to be speaking to Evan------basically encouraging him to give in to his rage, and explicitly stating that the only way for him to get stronger is to embrace his darker side. You can tell by his shirt collar that Evan is wearing the school uniform, so he's at school.
The only wavy-ish red-haired woman, who also happens to wear dark lipstick, we've met so far is the seemingly over-the-top headmistress.
We don't know much about her yet, but we know that she's also the one to come up with that super difficult month-long survival test to weed out the weak from the strong. It's kind of an inaccurate plan, since it didn't require the students to go all out with their powers, but I'm guessing she needs a magically strong, emotionally unstable, young and impressionable person to go through with whatever plan she's concocting. And she's chosen Evan