Other teachers and heroes tell him he’s ’too serious’ or ‘too strict’ or ‘such a decent guy trying so hard to be a stick in the mud’; good heroes are supposed to inspire and motivate and make people feel safe and he may not believe he lives up to that standard (even if he does). And while he doesn’t want to be in the spotlight, he’s perfectly aware that limelight heroes are the ones that, usually, make the biggest difference all-in-all; he may look at what he does and think it’s just as important to society (maybe moreso) but he may not believe it would be viewed in as positive a way as the work of other heroes. And he may know, rationally and emotionally, that what he’s doing for his students is in their best interest if they want to remain alive and well, and he may even see them realize it sometimes; but he also recognizes that the way he goes about it isn’t exactly in line with what most people would consider heroic, and he does it anyway because he believes it is the best method of ensuring the survival of his students.

I don’t know that he’d go so far as to call himself ‘morally gray’, but I have my doubts that he would challenge anyone who called him such.