>>285527709
Shapekeys are vertex modifications that can be applied dynamically; it's how visemes and emotes work in vrchat, all the sliders in koikatu/cm3d, etc. In blender, you can apply the shapekeys in mesh object's data properties tab. Just drag the sliders for each shapekey and the mesh will change in realtime. You can also change them in unity, which may be easier (since you have all the shaders you want as well). They're under the Skinned Mesh Renderer component for your body mesh.