Well, it turned out that it's not as easy as I thought.
Kva you did again, you really are a machine of creating awesome things.
Well, it turned out that it's not as easy as I thought. 
Why? The skeleton mesh has the wrong bones?
EDIT
Forgot to say, this is BEAUTIFUL!
Wardrobe mess with the internal skeleton and all turn into a big mess?
Why? The skeleton mesh has the wrong bones?
No internal skeleton works fine, but it loses its own texture, вut this is not the main problem. Also I can not make a transparent skin.

Character is largely hardcoded.
Wardrobe mess with the internal skeleton and all turn into a big mess?
No, this model works fine, but it looks like an ordinary blue human.

It is necessary to solve two problems:
1) The main task - to make a transparent skin.
Now I do not know how to do this. Perhaps we should try some variations with [WARDROBE_FEATUREOPTIONS].
2) The second task - the internal skeleton.
I believe that this problem can be solved by [FEATURE]. Ie this should be done like the engineer backpack - a separate model with texture that is attached to the character model.
Damn... so close to a playable spectral race...
Well, there should be a away to make the skin to be transparent, after all the
**** dead characters are fully transparent, with wardrobe an all. But if this is a hardcoded thing, that's a bummer.
I'm having some difficulties with the models in the editor. It seems to make spectral animals are not so simple.

But the skeleton is working fine, I tried to do different death animations(in *.animation) - cutting off the head, legs and body.