It's probably something very standard like a new arena. multiple arenas, or something for KAF, or maybe it lets you do dif fatality moves....I dont know. A new vault or dare a i say...new fighter. would be nice. or even the final fmv ending which I really dont think is likely. I"d say it is prolly stuff for KAF or an arena mostly likely.

Hmmmm. maybe Shinnok's Sanctuary's first floor might hold a clue with the order of the skull columns you have to destroy. Just a thought.

I've been trying to get someone to try a few codes, and I was referring to the example I gave. Someone tried and debunked the possibility of using those codes, which are from previous MKs. Versus screen codes, which was something I thought it might be for.
Apparently there aren't default symbols, and you have to six symbols, so that at least debunks the examples I was talking about. There might still be a more complicated variation, but that might be a little harder to find than eight possibilities.
[And, I did also get him to check the profile codes from DA and Deception, just for fun, but they didn't work either.]

A post I found on the MKA Forums.

hmmmmmmmm.........

I heard but I still dont know wether or not this is true cause there are idiots at gamefaqs that say it might be the ability to use dual blades and pulse blades for the create a fighter. If you do look in the KAF mode you cant assign a pulse blade as a weapon. But like I said, I still dont know if its true and I am still looking for the code.

For anyone who is still curious about using the Action Replay... don't bother, it just freezes the game up. (Freezes at the Dragon Logo right in the very beginning) I guess the codes are just bad from that site, I'll wait for code junkies version of the codes (if it's different) if the actual code still isn't revealed by then.

Codebreaker works, i used it for my coins.

i just tried codebreaker and it doesnt work for the code, I did unlock all krypt, and got everything except for the ? box.