Wait, are they mummies now? I gotta say, they're a lot less creepy like this. I liked the idea of the Nyx being this intangible dark presence, like more of a terrifying abstract. That made them seem more dangerous to Laine, I think.
I must agree with BP on this one, having these as minions of the Nyx work well, but the Nyx themselves were really terrifying as this amorphous non-corporeal entities that fed on fear. They always reminded me of the creature that lives under the bed or in the cupboard, real old fashioned childhood fears.