Oh dear. Does Pewdiepie have any idea what he just unleashed? This is going to feed people that live for this stuff for months.
While he obviously got somewhat exposed here, because it seems he has probably used the word before, I do feel there should be a moral distinction between using the word as a general expletive and specifically directing it towards black people. Those two things aren't the same. Neither should be done, but they're not equivalent.
I still don't think he's the kind of person who would use the word in its original US context, but I may be wrong. Either way, he's an adult male shouting the n-word while playing games on the internet. Maybe it is time for him to reflect on that.