"The next day, he did return with more questions, these ones very specific. He wanted to know about the vampires of eastern Skyrim. I told him about the most powerful tribe, the Volkihar, paranoid and cruel, whose very breath could freeze their victims' blood in the veins. I explained to him how they lived beneath the ice of remote and haunted lakes, never venturing into the world of men except to feed."
"Your advice helped me very much," he said. "But you should know that the Volkihar have an additional ability you didn't mention. They can reach through the ice of their lakes without breaking it. It was quite a nasty surprise, being grabbed from below without any warning."
Never says that they cannot blend in. This section pretty much tells me how they prefer how to feed and trying to animate something like this is hard but personally this is the reason why my vampire character specializes in ice spells. The volk vampires in the court do fit the cruel part of the description.
