I didn't discover it by myself, I saw it posted in another site, try it if you like. I will try it now and see if it works.here it goes:
Ok guys, first of all i assume konquest has to be beaten to do this. You must find do the missing raiden's staff mission first. (If you dont know then go to FAQ's side missions) Afterwards you can find raiden in outworld speaking of FUPA (which we still dont know what it stands for) and speaking of a recleansing process that needs to be forfilled in earthrealm. You will find nightwolf in earthrealm were the previous cleansing process was done (retrain mode) Retrain with nightwolf head back to raiden
and he will tell you to run another side mission to find the reluctant stryker in orderrealm to devise a series of troops w/ hotaru. Finally go back to raiden one more time and he will award you with a key the end of it has a mortal kombat symbol on it. We've tried this key at many locations and only one came to mind When looking at the key in the inventory it says "To the gates of purity on the 11th moon". And what do ya know the village gates open on the first day of november. Thats alot of meditating beware but some may already be close to that month. Ok so here's where it gets good, you enter the village and there stands the elder gods. (Nice Cinematic Video) , and unlocks a new menu on the arcade bar, a second page with 10 grey slots. 2 which are colored in with the faces of Jonny Cage and Sonya. Hey i hope this all helps, im gonna jump on ps2 online and see if i can use them there Peace