Well after a LONG ass time of playing Konquest mode and recording the backwards language of the Netherrealm denizens I think I have found two secret characters: KITANA & QUAN-CHI!
Go to the Netherrealm and first look for an armless guy around Moloch. Talk to him a couple of times and on the third time he will say:
"Find Quan-Chi in Chaosrealm..."
Next go to a zombie soldier around the city (I think he walks around Shinnok) and talk to him a couple of times and he will say:
"Kitana is here..."
So now all I have to do is fine them BUT more news I did find out some interesting things from other people too:
"The Lizard is lurking"
"Rain is purple right?" (I think that's what he said)
"The One Being will return"
"2007 will be here sooner than you think..."