No idea what it opens...
I finished Konquest again last night. This time through I tried to complete everything possible before meeting with Onaga in the Portal. I was able to get most of it and even some quests I never hear dof before. Basically, when I get Raiden's Staff, I took it to Kung Lao who gave me 600 Gold and told me to take it and stop Shao Kahn... so I go to Shao and he says I'm not out of his good books yet and I have to go talk to Reiko about not sneaking into Shao's quarters and wearing his helmet anymore, LOL! Anyhow, I'm still convinced that there's something else you can do with respect to that. (Mind you it also might be open-ended like Shao Kahn's men asking about getting information regarding Sindel's capture which they do nothing if you talk to them After you find out about her.)
I personally believe that there are more quests out there to find but I guess it's a matter of who and how to unlock them.
And dammit, I still can't find Kintaro in Edenia! ARGH!

Yeh, few days ago I saw Kintaro for the first time in Earthrealm. Pressed vigurously, nothing happened. Heck, what does that key open?

Which key?

I believe that key (earthrealm disappearing ninja boy) opens one of the huts nearby. The hut contains diff. kinds of koins.

um.... how do i get Raiden's Staff? and then where is Kung Lao for me to take it to?
well i was gonna stop playing Konquest cuz i just finished unlocking every thing in the Krypt but this Raiden's Staff stuff is interesting me and id like to help find out if its possibly connected to a SU or some thing.
o i got an idea what the secret key may go to (although i dont have it nor exactly know of what quest ur talking about)..... perhaps to the vilage door in Earthrealm? i went over there and tried opening it and its locked. maybe u can use that key to go back there and MAYBE find a SU or find a clue or some thing. or perhaps the u can use the key to open all locked doors?

No, it apparently just unlocks a hut nearby for Koins... doesn't unlock the gate, I tried...

k but... how do i get Raiden's Staff and where is Kung Lao located so i can take it to him?