Short one shot, which i decided to post as I have a bit of writers block on my other story.

Yassen never really looked in the mirror. Some would say he was a bad man, a few others may say he was good, but the truth was that he was neither. That was what his mentor, Hunter had taught him all those years ago.

Several years earlier

Yassen had already killed on two assignments before and the last being his third but the first where he killed someone innocent. He had made a mistake, she saw him and he killed her, simple as that. But somewhere in the stone heart of his, a crack appeared. Hunter was different to other Scorpia members, he still remembered his words to this day, he didn't say suck it up or its going to be okay but "Your not a bad person Yassen, no one is and neither is anyone pure good. People are not good or bad, their just people. Anyone can kill a hundred people or devote their lives to saving people, for some, yes it is easier than others but a saint is perfectly capable of killing someone. Just you remember that. Your not a bad person Yassen, no one is."
End

It was those words all those years ago that was one of his main guidelines. Nothing is black or white.
He would find that his mentor would die, then he would meet his son Alex and then he would discover that Hunter worked for MI6 all along and that he was a 'good' guy. But as John said all those years ago "people are not good or bad their just people".
Yassen looked in the mirror. He was grey as John called it, in between black and white.
But no matter how many people he killed, or how much he tried to help Alex, he was just a person.

What do you think?
I completely agree with Hunter/John no one is pure good and incapable of turning bad, and no one has never done something good in their lives.