[quote=Palamon]
Already on it, gotta human incoming, you seem to be lacking those.
[/quote]

I think we have a few in the works, just with sheets needing to be submitted. Might be worth contacting Terminal, Saint and Flagg to see the world building they already did for Mortal Plane. 
Alternatively, you can PM me the basic idea you had for a Demon Lord and we can work it together? I feel like more Planes need adding.