The Shadow Knight's Letter

Hmmm? How did you end up here? You don't look like you belong up here yet. You'll need to follow the proper procedure of this training center and move up from the very bottom.

You still haven't headed out to meet Mu Gong yet? I told you that you can find the back alley that leads to the top near the green flag behind the Mu Lung Dojo Entrance! Hurry!