Instructions
Play and beat the "Mortal Kombat: Deception" Konquest mode. You win this mode by fighting through eight levels and beating the final boss.
Return to Konquest mode once you have beaten it once. Select the "Edenia" level.
Walk along the path until you reach area G-8. Go inside the tent and press the "Circle" button to enter meditation mode.
Select "Friday" as the day you want to stop meditating. Select "12 a.m." as the time.
Exit the tent and walk behind it when the meditation period ends. Press "X" to open the chest and receive the Liu Kang key.
Return to the game's main menu. Scroll down and select "Krypt OT." Highlight the "Liu Kang" coffin and press "X." Liu Kang is now playable.