A short summary of events before MK:C.
Chapter 0
Before MK: C
Shao Kahn attempted to take over Edenia 10000 years BMK. However, during the 8th tournament of a series of ten, an unknown Edenian defeated Shao Kahn's chosen warriors, saving Edenia form merging with Outworld.
However, Shao Kahn challenged Edenia 6000 years later, in a new attempt to conquer Edenia. After nine consecutive Outworld victories, King Jerrod ordered Jade, Kitana and Edenian soldiers to search for new recruits, able to win the 10th tournament.
Kitana, at that moment 8000 years old, was sent to Earthrealm multiple times, finding new warriors to fight in the tournament. But one time, the warrior she would encounter, was not a one she expected to find.
The storyline is based off of MK (2011) with some timeline changes, so it fits together. This summary is only for people who would like to know why some things are different than in the games (I don't watch the movies/read the comics/etc.).