The only way I could see a Werewolf appear in a Mortal Kombat game is if a previous character has the ability to turn into one. Night Wolf I believe should have a fighting style where he can transform into a Were Wolf due to his shaman abilieties and have an arsenal of powerful moves.

Picture a Were Wolf with Night Wolf's clothes and the face paint over his eyes. The Were Wolf could drool and have sharp claws the mangle his opponents. As mentioned in his Deception bio, he had undertaken the role as his tribe's Sin Eater and had wandered the Netherealm with the curse in his body.

I believe that when in the Netherealm your body slowly changes and in Night Wolf's case I believe he would slowly transform into a Werewolf. To make sense of this I believe that Night Wolf keeps his human form by use of Magic. Night Wolf's quest in the next game would to dispose of this curse to his body and he goes on a quest to vanquish the Were Wolf curse in him.

What do you all think of this idea?