For Fane (or Custom Undead) you just need to keep ANY armor on "legs", "chest", "feet" and "head".
I have a custom undead who is wearing a cap. You can see his entire skull head, but nobody responds to it because he's wearing a helmet (that's with the helmet being displayed of course).
I have a feeling that while the MASK itself is cool, I'll probably end up only using it for social situations, because you lose out on the extra armor et al from not wearing a proper helmet.
Last edited by KentDA; 17/09/17 12:04 AM.