So about Kori "killing" Shan Yu, this shouldn't really be a shocker, ngl, as I've stated this already in a previous chapter, but Kori literally said he wants to be willing to make hard choices that all might wont make. And you cannot compare it to the truck driver incident at all, your a comparing a innocent man to a mass murder any resonable normal human would feel less empathy for such a scum and one person comment not going to call out names said kori was 12... which doesnt really mean anything when we consider he was already mentally older when he was three..... kori mental age by now is that of a grown adult(do note that doesnt mean he will be serious all the time or something).
If you have any other questions, I'm willing to answer to clear up any confusion.