this is a very stupid idea.. to take the joker's fatality from mk vs dc and make it gory... this is just a waste of a fatality slot.
Are you completely sure this is real? Shang Tsung's costume is that from MK v DC, not to mention the inputs shown in the video are of a different look than MK9.
Also, the Joker animation is the EXACT same. This could be anything from a mod, to a placeholder. You can't rule anything out, however.