I don't believe the transformative powers are exclusive to the staff. Based upon Lucians explanation of his newfound shapeshifting powers, it is likely all Greys have the ability to use it, but they lack the knowledge and insight to do so. The dragons (like Emiline) all know intuitively how to do this and have greater power and control over it (The dragon blending in with the night sky, shapshifting an extreme amount of mass away and impersonating the commissar (though they seem to have trouble with their third eye))