Board Thread:General Discussion/@comment-18987589-20130818085612/@comment-422853-20130824061923

Sub-Zero's arcade ending is obviously non-canon though since he had become a cyborg.

In any case, with MK9 he had been on a misguided quest by fighting to "avenge his brother's honor" when he faced Scorpion, but after fighting Noob Saibot later on he would no longer think highly of his brother obviously, so maybe things will be different should Kuai Liang happen to see Scorpion again.

The only way I see them maybe being friends though is after Scorpion learns the truth about Quan Chi being his family's real killer (again) which then he and Sub-Zero have a common enemy... I'll leave the rest to your imagination.