.... interesting topic
Before we knew all bios and endings, I thought that Havik was the one who reanimated Liu's body, just to create Kaos.
But having seen no mention of this on the game yet, I'd say that the MK Team is undecided at this point, and will be a plot point in the next MK.
I don't think it was Onaga, though. He couldn't have entered Earthrealm without being noticed to revive a mortal.
My money is still on Havik

Perfectly said bro.
I was playing MKD for hours today and while reading the bios/endings, I was wondering about this.
All I know is that Liu kang is definitely one of my favorite characters once again, before his zombie form, I hated him. But not only did he get an amazing new look, he also got an amazing new story.
Liu Kang rocks MKD.

I was like that too. I thought Lui Kang was a fruit before Deception, but now that he's a zombie, he's dope as all hell.
But, I suppose I should reveal the truth. This isn't confirmed yet, but it's a theory. Okay, so there's this guy named Statik(I won't go into detail, but if he's in MK7*crosses fingers*, you'll see his whole story). At the time of MK 1, he notices a huge power, and it belongs to Lui Kang. Blah blah, shit happens, blah blah, MK Deadly Alliance time now. He approaches Kang in hopes of getting trained, but as he comes, he notices Tsung and Quan Chi killing him. Blah blah, he finds a black magic book, revives Kang's body in hopes of it training him. Reverse effect: Kang retains all knowledge, but isn't a "good guy" and attacks Statik. blah blah, etc etc, Statik cages him in Outworld. blah blah, Deception comes, kang breaks his way out, and yada yada.
I might post "Statik's" whole story later on, but right now, it's only developmental, experimental, and able to be discarded. If I do post his whole background, maybe you'll like it, maybe you wont. I could care less, but I think he's pretty interesting.

ED Boon revived him, no question asks.

So... Ed Boon is Havik? Uhmmmm..... yes, he's the "master of chaos"

though havik is a good way of having liu kang come back...i wouldn't really bet on it.....as you can clearly see by his ending.....he DOES NOT have the power to raise the dead i.e. he had to steal the heart of onaga to ressurect shao kahn (if his awesome ending is in fact true) so i don't think it's havik though it would've set up an awesome feud if liu kang is back in the fold.....which i hope he isn't

I can find no fault in your logic.

Onaga doesn't have revived Liu Kang's body, because if he did he could give him a great status...........like his guard or something.
the body has posses great strenght so it would be very difficult to defeat Onaga when Liu Kang is defending him!!!!!!!
alright we know that Liu Kang's body has killed many people which maybe created chaos.that's why I am so sure that Havik is the one who revived the dead body of Liu Kang.
anyways Liu Kang is the best fighter who I know in the whole Mortal Kombat.He is a fav. of mine, I really like his bicycle kick, Flying kick and his Dragon Fire.
his apperence was in every mk:
mk1, mk2, mk3, mk4, mk 5, mk 6
yeah he actually even made it in mk 5, the intro.
still in his absence he was very important in the game!

If you watch the ending for Liu Kang, there is a guy in the lower left corner of the last still shot that looks like Raiden with electricity coming from his hand....

Ed Boon's the master of not being serious(see "fight night". I still can't believe he said "Hiz-ouse". He said that before fight night actually begun).
Using process of elimination, I'd have to think it was Onaga.

Look. Onaga revived Liu Kang's body and used it "as a tool of destruction. Liu Kang's soul first freed his friends from Onaga's control with Ermac's help. He then sought out his body, and they fought in a cataclysmic clash that spanned across realms. However, they're both Liu Kang so they're both equal, so Raiden intervened and zapped the two of them together. Think of it like the Matrix Revolutions, if you've seen that. Neo and Smith are opposites, they're equal. Their fight would have gone on forever if the Oracle hadn't intervened and helped Neo see the right path.

THe thing that revived him was obviously the higher power mentioned in Ermac's ending and bio that he mentioned to be shaping the fabric of the realms (or something like that) and controlling Onaga and Shao Kahn. They are both mentioned as an unknown force, and i believe that it will play a major role in MK7 as well.

I believe that Havik had took possesion of Liu Kang's body and used it as a tool of destruction. Havik wanted to maintain chaos through all of the realms, I believe he thought that Liu Kang was such a great warrior and needed to use his combat skills.
In Liu Kang's ending I think that when Liu Kang's spirit reached his body in Earthrealm and both were at a stalemate, I think Raiden had come along and stopped the fight by merging both beings into one.
With the fusion of the two beings, Liu Kang's mind would take possesion of his body once more and Liu Kang would return to the state he was in before the Deadly Alliance ended his life.

If thats a fake...I can tell you its a VERY COOL fake.
That story actually has potential, and I think its amazing. Now it all depends on how this STATIK character is.
Care to go deeper in his story?