How to mix animations with different mask into the same layer in Mecanim?

I have 2 animations torch idle and torch attack, both are full body animation in the fbx.

I want the torch idle affect only the right hand and torch attack affect the full body.

So I mask torch idle as the image and kept torch attack untouched.


My controller has two layers, Base Layer containing locomotion and Torch Layer contains the two torch animations. Torch Layer and has layer weight 1.

The problem is that torch idle overwrite the Base Layer base locomotion.
Making a weird pose:


Torch Layer layer weight 0.5:



left:locomotion idle | right: torch idle


Please help!
Thanks