Once again I'm delving into the depths of A7X fiction without having much of an idea about who is who so this could get interesting!
I liked the repetition of 'fake', the idea that word conveys, that they never really knew the real Zack, just a mask. Then the contrasting emotions of wanting to help and yet finding yourself up against a brick wall, when somebody just doesn't want to be helped.
I laughed at the 'But that is besides the point.' part, after that seemingly random information you just went and confirmed it, ha! It makes this character seem so distracted, like their thoughts are going at a million miles an hour.
Ah, the should of's and the could of's, that guilt that you never really did enough! I liked the way you were writing the guilt in, so matter of factly does he blame himself.