Can't you just use the original fbx and edit that? I'm not much of an expert on this but i just take base models, remove stuff i don't want in blender, add stuff i do, fix it all in unity (because the prefab dies) and the boom.
@voiiidwalker Bloodborne is pretty good but not that good with vcc from what I've heard. It's pretty good but I would only recommend using a custom sdk currently instead of a patched one if neccessary.