A new idea for the Ninja job!
I think it would be neat to see a shadow clone concept similar to naruto. A few possible ways to develop the concept could be one of the following.
A. It could be a 15 or 30 sec. Duration and the shadow clone mimics your moves.
Or
B. It fights on its own accord x amount of duration.
Or
C. It blocks the next attack that is directed at you.
And then to have even more fun when we all get stronger you could perform the multi-shadow clone allowing 3 or so clones to appear.