[@Ollumhammersong] The Thousand Sons *are* more powerful than other legions. Yes. 1v1, would generally not be a contest without some kind of special advantages. You need to realize that. You also need to realize that I am not a douche. I can intelligently play this character. 

The Khornite would probably be the most difficult to fight, because of the specific gifts he would have from his god. I would expect him to be more than regular traitor marines could handle 1v1 as well.