i know blendshapes are useful for animating facial expressions. The orginal geometry is the base shape, and then I have the target shape. Once the target mesh is deformed you can key it and then with the blendshape slider it then morphs between the two.

Oringally I had only the head as my target and I deleted all my faces. but it didn't want to blend with the base of the character since it was the whole body. I believe the geometery has to be the same starting mesh. But after I create the blendshape I could just delete it right?