Episode 8 got me thinking, how did quan chi morph into sub?

In the official ep 8 thread I posted my thoughts there, I just wanted to delve a little deaper here.

I say Quan used Shang to morph, that that was Shang's purpose for being there, as well as for Shang to represent Kahn's will. Quan and Shang combined their magics to allow Quan to assume sub's form, abilities, and fighting prowess. But wait! Theirs something missing in this formula...Sub's soul.

The Lin Kuei had a vested intrest here too. Did Quan request the "help" of the strongest Lin Kuei warrior? Of course Sub wouldn't WANT to give up a piece of his soul, but he'd do it to please the grandmaster.

Shang plucks a piece of Sub's essence, and with the assistance Quan's magic, transplants it into Quan Chi in order to allow him to directly manipulate a soul without any consequences or added "curse" effects.

QUAN CHI IS THE MAN!!

Following this path of events gives him even more insight into Sub's psyche, and possibly even more sway over him. It also puts him on the path to taking scorp just as was shown in the episode.