I created this plug in just in-case someone only wants to use the robes and not the entire Mod 'Castle Volkihar Redux' mod, which makes Volkihar the size of a city. The set is highly enchanted and could be considered a cheat. They are also sold by Alu Disciple of Molag Bal in the Castle Volkihar Undercroft.
The Robes of Molag Bal is a small mod that features the ability to craft the entire cloth armor set.