I have kept wondering about why the writers have transformed Chuck into such a dark character in Season 6.
He is definitely not the same Chuck than in season 4 or specially 5. And I am not talking only about the spiraling down of the 2 last chapters, this has been a constant from 6x01. Every harsh look, every cold movement seems to be well planned with an intention (for example when he is not able to look at Blair eyes in last chapter, when she appears like the crazy stripper)... he looks so...bitter, so much obsessed, almost insane. Even when we all know how much he loves Blair, he is still cold and hard with her many times,not like in the past.
For me, this is something deliberate, there must be a reason behind. Maybe they are trying to make a parallelism with the psycopath monster that his father is? Maybe is it a way of showing he is controlling himself not to jump on her and ravish...?
But I really hope at some point in the two last chapters we will take to see again the "evolved" sweet at moments, fun, caring for people version of Chuck, maybe starting with the farewell scene on 6x09. We do have to see him before the end.