Falci: It's the second SubZero. The First, from MK1 is Noob Saibot.
Also, apparently Sub is on a vengeance agenda agaisnt Scorpion for killing his brother too.
Elder SZ
is NS? When did that happen? I thought younger SZ was best friends with NS, or Smoke/Cyborg Smoke. Come to think of it, what's the deal with the NS/Cyborg Smoke tag team? Does the one have psychic possession of the other or something?
Anyway, at the end of MK4 (it was either SZ's or Scorpion's ending), Quan Chi had SZ on the ropes, and reveals that after the elder SZ killed Scorpion, Quan Chi went ahead and murdered his whole family. Then Scorpion appeared and mortally wounded or knocked out Quan Chi, and told younger SZ that his vendetta was over now that he knew Quan Chi was the one who killed his family. SZ walks away, and Quan Chi gets back up and starts to cast a spell to banish Scorpion back to the Netherrealm, but just as he finishes, Scorpion grabs him and literally drags him back to hell. And that's the setup for MK:DA