I think what I'm going to do is delete the polygons and try to import just the bones. And if that doesn't work... well, I got a few tricks up my sleeve.
We'll see.
Edit: Well, my plan didn't work. Luckily, I was able to get it working with Meta Knight's sword, so I guess I can keep it like that for now.
Now, set the cull to 'cull all'
that'll make the model not be rendered.