Is Shao Kahn Raiden's brother?

I know it was something in the movie, but I realized the other day that I don't hear about it in any of the games even though it feel like they hint that there's a personal beef between them.

Did they ever retcon this or is it like an MLP thing where it's purposely left vague so fans could have their own theories that're as valid as anyone else's?

Solution 1:

All of the canon information for the games can be found here;

http://mortalkombat.wikia.com/wiki/Raiden

http://mortalkombat.wikia.com/wiki/Shao_Kahn

There are currently two timelines. When the game rebooted at MK9, it starts from the first tournament where Raiden does do the same mistake of defeating Shao Kahn BEFORE Kahn entered the forbidden earth realm. This action eliminates Shao Kahn for good at the end of MK9. Shao Kahn is a resident and the emperor of the outworld, whereas Raiden is a god. They have different species. So they can't be relative in the game series' setting.