Sorry dude thats not a big secret.

yeah Kochal the portal has been known for a while now.Kinda worthless imo for just 1000 onyx coins.

It's no secret at all...
Edit: By the way, Kochal is a three headed demon.

The rumor going around is that it's another "Ermac-ism" and that "Kochal" stands for "Koin Challenge".

Someone had played a voice from a citizen of the netherrealm backwards, and heard "Kochal is a three headed beast". Plus you see three skulls there, which makes me think that kochal was that chimera that was going to be the sub boss, but the MK team decided to take the skulls of it, and make those lava fountains out of them.

You said you went through twice? Yeah, that's what I've been posting about too. Why would they let you just walk through this portal if you haven't beaten all three? I mean even though the red thing doesn't show, you can still walk through with kabal standing there. You would think that that would be significant, but it doesn't do anything!
My guess is that the above poster is right. It was supposed to lead to something else like a sub boss or whatever(Edit: probably to Quan Chi's fortress in the production art because that would fit with the story), but they must have got lazy in the end and just left it and put a chest there to piss you off.

unfinished konquest?? what a surprise, kinda like the missing Sindels ring quest.

They really deserve an ass kicking over that one. Making it REALLY sound like Kochal was a character is not a cool thing to do to the fans. Not as uncool as having concept sketches of Pit Fatalites in the last game but not actualy having them.
I don't think that people are being whiny or want too much by wanting hidden stuff in the game. If they wouldn't keep giving people the idea in the first place and have a history of putting stuff in they arn't delivering on then it wouldn't be a big deal. Nobody ever says hey. Street Fighter sucks because there are no cool secrets. Its not a part of the game history.
MK has this history of secrets. Naming a porthole and saying you can "Awaken" him is fuel to the SU fire. 1000 coins is not a "Reward". You can pick that up anywhere. They had to know it would be misleading. People that couldn't see that couldn't walk and chew gum at the same time let alone make a bigtime video game.

Maybe, you need to enter the portal at a specific time, and then something interesting supposed to happen. It is just a thought

So how do you get this quest? LIke where do you go to fight these three characters?

yeah... Kochal is a 3 headed red dragon... Kira, Kabal and Kobra are the 3 head :(

This is just a thought I had the first time I unlocked this portal. Maybe it's a play on words.
Notice it says "Defeat your oppenent to awaken Kochal." Could it be that you have to unlock coffins KO, CH and AL in the Krypt in a certain order or at a certain time?

Kira, Kabal, Kobra? KKK? OMG, Dave Chappelle's white supremacist character is an SU!!!!!!! I need his for MK online!!!!