This idea was for Shang Tsung. Personally I liked him the best in MK2 as opposed to MK3. The idea in this concept is that his special move (flaming skull) drains his energy and because of this he transforms into the old man while he performs the special.

I darkened and changed around the color hue of his flaming skull special effect. You'll also notice I changed the sprite for Shang Tsung to raise his knee up like he does in MK3. He didn't do that in MK2 or MK1.

Also, when he is knocked down and defeated at the end of a match, he transforms into his old self.

During his victory pose he also transforms into his old self to "conserve" his energy for the next match.