Shinnok.

I say Shinnok because he saw the bad/evil within him.

Variations

Fire God- Charred/Burnt Liu Kang
Walker (zombie-think The Walking Dead)
Elderly

I think Shinnok and QuanChi are going to resurrect him. I can see QuanChi offering Liu Kang a deal - Agree to willingly fight for the NetherRealm in the coming war, and QuanChi would then release the souls of his allies. Shinnok would even "enhance" Liu's powers to godlike.

This theory would explain how some of the dead warriors from MK9 return. It would give us the Fire God from Liu Kang's MK9 ending. He could still be pissed at Raiden (and even exact his revenge) but still maintain his Heroism by agreeing to sacrifice himself to Shinnok.

My ideas for MKX Liu Kang...

Universal Specials - Fireball, Flying Kick, Kartwheel Kick

V1. Shaolin - Adds the air fireball and low fireball, adds bike kick

V2. Fire God - Adds fire to Liu's combos (much like Raiden's Thunder God Variation)

V3. Dragon - Liu can summon 3 "fire dragons' which circle him, much like the Injustice Character traits of Black Adam and Batman. They can be used for protection or sent out as projectiles.

I actually like this. Otherwise, Liu really has no purpose in the game.

I could get down with this. I'd still prefer him not be a boss though, no matter how "god-like" he's become.

Of course you know someone as treacherous as Quan Chi isn't going to hold up his end of the bargain. Watch Kang kill Quan Chi before Scorpion...

If Liu Kang is alive and he becomes elderly it looks like NRS will be disregarding the idea that the Mortal Kombat champion gets to stay young until s/he is dethroned as champion (even if he got beaten in the events of MK3, that wasn't a tournament at all). Which wouldn't surprise me considering their track record of forgetting about everything except maybe the absolute bare-boned story-telling structures.

I still think it's possible that Liu Kang survived, even though he wasn't moving and showed no apparent signs of being alive. I know people are still debating that, but we'll find out for sure in about a year, and I'll admit if I end up being wrong. I'd be happy if this turned out to be the case.

Raiden did take Liu Kang's body with him, Johnny, and Sonya at the end, and we know that Raiden knows how to resurrect people. And even though this isn't dark Raiden, we know he's amoral enough to trade other warrior's souls to serve Quan Chi in hell (or at least be willing to), so he probably won't care about the immorality of resurrecting someone either.

We know that Quan Chi was hiding somewhere in the shadows at the end, but I think the idea was that Shao Kahn GAVE him the souls of the other warriors, through Sindel (who had Shang Tsung's powers) or through Shao Kahn himself. I don't know if Quan Chi has the power to take souls himself in MK9, and even if he did, I don't know what the requirements are (i.e, does the victim have to be killed by him or someone on his side?).

First two options seem more likely, but anything could go. I don't really know whether to trust the article either. I think it's possible Liu Kang might not be in at all.

Raiden took Liu Kang's body when he teleported Sonya & Johnny away at the end so he's got him. If anyone it'd have to be Raiden. He's done it before.

Raiden probably just gave him a proper burial at the Wu Shi Academy. Then QuanChi comes along and resurrects him.

I thought this was worth mentioning too: Remember when QC resurrected SindeL? She looked perfectly healthy, not zombiefied. She just had white eyes and a silver streak in hair (which could've been there before her death anyway)