MOTION on mask from Illustrator

If you want to use a vector path as a motion path by a simple copy and paste, the layer cannot be scaled, moved, or rotated. If you use a shape layer, the default anchor point of a shape layer is 0, 0. When you convert a vector layer from Illustrator to a shape layer, the anchor point is at the center of the layer's dimensions. This offsets the motion path. To fix the problem, you have first to convert the Vector Layer to a Motion Path; then you have to copy the path (easiest to do if you set a keyframe and then cut it), then paste the motion path to a null layer. Then you have to add a new null to the composition at the comp center, parent the moving motion path null to the new null, and re-position the Parent null to 0, 0. This will line up the moving null with the original motion path. 

The other option, and the one that I use most often, is to select the path, open the Window/Create Nulls From Paths script, and choose Trace. You can then add a second null, parent the trace null to the second null, then use the pickwhip to tie the position property of the second null to the Transform Group/Position of the created shape layer path. 

If that does not solve your problem, I don't understand what you are trying to do. 

Not sure what you are asking. You can use the shape and mask at the same time. If you can#t resolve your problem with a single layer, use multiple ones.

Mylenium

Create a feathered circle e.g. with the Circle effect, copy & paste the path to the position control.

Mylenium