Even if The Scar is working for someone else, he is still a heel and has absolutely no redeeming qualities. Anyone who would work for someone like that is not a very nice person. Rather he or she is someone who lacks principles. Thus, The Scar is still one of the bad guys even if there is someone else above him who is in fact the antagonist or "principal character in opposition to the protagonist or hero of a narrative or drama."
http://www.thefreedictionary.com/antagonist