Cybella Sieyes

My suggestion to you on how to go about this sort of garment is to "fake" the poncho effect with full fabric arms and a loftier body panel. Seperating the mesh into arms and a body will allow you to keep the alpha through AO motions. It is not as simple an item of clothing as a poncho in RL but if you make the mesh baggey enough you should be able to fool the eye watching into thinking the garment is poncho like