Before everyone starts jumping the gun and sayng Lui returning as a zombie and ghost should think of the possibilities of how cool this could be first.

My theory is that Lui Kang will be seen in two different forms in Deception. One form will be the ghost/spirit/soul form where I think he confronts Earth's warriors and tells them of the Dragon King's return(if Raiden isn't the one to tell everyone then Lui is). Plus, I think he tells them that his body is under the control of the Dragon King as a sort of protector until he has regained all of his power.

Now this is Lui Kang we're talking about here people. Whether you like him or not, he's a badass character in the MK world. He single-handedly defeated Shang Tsung, he beat Shao Kahn twice, and even fought Shinnok who was a former Elder God. He's not some chump fighter, even in Deadly Alliance he was caught off guard and struck in the back. It looked to me like he was about to finish off Shang again. Which leads to my theory on his second form...zombie!

The Dragon King has returned, but he's still not as strong as he used to be so he needs time to rest and regain his strength. He asks his new servant Reptile who would be a worthy protector for him...Reptile knows only one person that could hold off Earth's warriors and thats Lui Kang. He unearth's his body(it's not too long after he died so he wouldn't be all bones) and takes it to the Dragon King. The DK revives the body, but in a way that he can control it.

There you have it, I can almost gurantee you that Zombie Lui Kang(bad guy now) will be a sub-boss in Deception. Here you have Earth's warriors fighting a former friend and one of the greatest fighters ever. He'll be hard I bet you! They may even do the duel thing like in previous MK games where you have to fight two characters. What if you have to fight both Reptile and Zombie Kang at the same time!!!!!!!
EDIT: I forgot to mention that I don't think Lui Kang will be playable at all.