TRMK: When we last saw Sub-Zero he was made a Cyber ninja at the end of MK9. Lots of fans are asking why he appears to be a human form again. Is this something you are willing to elaborate on at this time?
Ed Boon: Yeah, that's easy. The thing about Sub-Zero is that there have been many Sub-Zeroes over the years. So the Sub-Zero that you see can be anybody because the
Lin Kuei has a sea of Sub-Zeroes. We do explain it in the story.
Full interview here:
http://www.trmk.org/features/interview_mortal_kombat_x_ed_boon_e3_2014/
There is also a video where he says also about it.
There is a new Sub-Zero in town, Bi-Han is Noob Saibot, Kuai Liang is dead, so Bi-Han as sub-0 fans, deal with it.