Ok so here’s a suggestion.
Give the humanoid Warlock Demons new player-like models that can use armor and allow us to give our Demons proper transmog.
You can base the Succubus on the Draenei model and the Felguard can be based on Humans.
Succubi should wear leather and Felguards should use plate.
It’s a glyph and they take the armour out of your bag. Be sure to have just one set or you gotta have to get another glyph to fix your fashion disaster.
To make the glyph, it’ll cost you your soul, dignity and a kitten.
Now that makes it far too expensive.
I already wear leather. And you can dress me up in whatever you want. 
No.
Go for it Mortis! Maybe she’s succubus bound!
No.
You can dress her up to be “demon food”!
(Psst… Mortis, you need to tell Blizz that the Warlock spell “banish” should work on Demon Hunters since they have demonic blood)
Oh… 
I am! Slayed a whole army of them!
Is there really a glyph that does this?? I haven’t ever really used them. 
Nah, it doesn’t exist. I was just playing with Mortis’ idea how Bliz would implement it. We DO have a glyph that makes your Felguard grab a random weapon from your bag.
What about me?
I’m sure you already have succubi you dress up. No need to expose the rest of us to them 
Also, I think all demons should be susceptible to DH attacks… even allied warlocks’ pets.
Oops, sorry my Immolation Aura killed your succubus. She got too close.
I like this idea. Would be nice to dress up my warlock’s demons a bit. The succubus is always moaning that she has nothing to wear.
Short answer: No.
Long answer: Nooooooooooooooooooooooooooooooooooooooooooo.