Soooooo... mc just casually forgot that that jelousy-blinded teacher led to literal kids seriously endangering themselves and others to the point that deaths could've happened if she (mc) in specific hadn't been the one targetted? Because it does look like that.
Like... come on. At least tell...
Aaaaaand of course, the annoyance that was gonna cause more blodshed has a little sister that is a half-blood. Let's start with the bets everyone! Is the little sister deathly ill with a sickness only the mc can cure too or not?!
If I am remembering correctly, she actually can and does in the heroine centric spinoff. She just plays more of her princess side with MC because she likes him and wants any advatange she can get over the other heroine, said heroine is aware of this and even comments on it.
You know, being blasted in the face with that much magic would surely cause brain damage. Perhaps that "curse" was the result of that, like how some brain tumors can change someone's personality for the worse.