You know we'll see at least one or more major plot twists in the upcoming MKX story. Here is mine:

I saw someone's post on a different site's forum mention the possibility of this MKX Sub Zero not being Bi Han or Kuai Liang at all, but perhaps Shang Tsung. Yes I know Tsung appeared to have died in MK9 after Shao Kahn sucked his powers from him and transferred to Sindel, but MK is known for "reviving" dead characters (Ex. Scorpion).

And if it's Tsung, I'll add a second plot twist: this Sub Zero doesn't reveal himself to be Shang Tsung until the very end as the "big bad". After all, Boon did say the big bad would be a "surprise return character".

If Tsung does come back and morphs as Sub Zero, it makes alot of sense as it would allow Tsung to "join" with the good guys by eliminating those who turned against him, such as Shao Kahn's surviving allies, challenge Raiden as someone whose reckless judgment can't be trusted and resulted in indirectly killing off the good guys with his poor choices.

Shang Tsung would target those who are the biggest threats to him, turning Raiden's Earthrealm allies against Raiden, and using them to defeat those who allied with Shao Kahn before revealing his sinister ways. Whether Shang Tsung, as "Sub Zero" goes as far as becoming Grand Master in the Lin Kuei by challenging other members like Sektor or Cyrax.