3. Arden Cho
Best known as the sword-swinging Kira on MTV's "Teen Wolf," she has also crossed into video game performance territory as Lara Croft's friend Samantha "Sun Queen" Nishimura in the Tomb Raider reboot. If Mulan is going to be primarily an action hero, Disney should definitely consider Cho.
If the film were to take a somewhat Ang Lee-style approach, we can be sure that the color palette will be striking, the editing will be kinetic, and the star will have to endure quite a bit of stunt work. And Cho comes with experience! She even had a small job as a stunt performer and acted as a Korean sniper in Olympus Has Fallen.