I have 2 deception theories, one IMO is highly possible. The other is more wishful thinking on my part.

Highly Possible :

The Liu Kang Ghost/Zombie is actually Shang Tsung.

Think about it, Tsung took Kangs soul AND, Tsung has extensive morphing abilities.

This theory makes so much sense and opens up awesome storyline possibilities.

One sub-boss is known to be playable. Let's say this sub-boss is Shang Tsung, disguised as Liu Kang! On defeating Liu Kang you get an awesome FMV showing Kang's spirit/Zombie form melting away to reveal Shang Tsung who you now fight again! If you beat him, Liu Kang is resurected in human form! His reborn human state is then the 3rd outfit possibility unlocked. Perhaps all this can only occur on Hardest difficulty?

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Wishful thinking Deception (still possible of course) :

Nitara shows false allegiance to the Dragon King and programs Sektor to act as his personal bodyguard. Nitara then plots DK's assassination with Lord Raiden, knowing that Kano is lurking in the shadows, listening. The fickle minded Kano tells the Dragon King of what he overheard during daylight hours (knowing Nitara being a Vampire will be sleeping in her Koffin) but fails to account for the souless bodyguard Sektor, as does the DK. Sektor has a secret Primary objective to destroy any who plot against his true master, Nitara and therefore attacks DK and Kano upon hearing their plans to have her exterminated for her treachery. Nitara has successfully deceived them all! Raiden and the forces of good included. With Sektor by her side, she rules a majority of the realms.