Now this is what a realistic sociopath story! Not a grand backstory, but a petty one. And it's most likely not this singular event, but an accumulation of multiple events that were filled with pettiness, that just made him eventually hate everybody, and even he hasn't realized it yet because he thinks of one event changing things like a book, like an equation in reason. And his personality seems like a perfectionist, it doesn't mean getting an A or anything, but to win and attain the goal. They don't really have motivations in life, they just need to be told the goal and they'll reach it. And if something gets in their way, they act petty and treat others as unworthy, or inferior. He's just simple, and makes sense. It's not bad character writing, it's just realistic writing on the most personalitys people always make overcomplicated by diluting in delusions, because they don't know what they're thinking. I can talk about detachments to emotion, but ever since the story from the beginning to now, he's become more attached to people, albiet, super slow. His character reminds me of a more social and less smarter Near from Death Note, just a thought.