[@Aristo] Don't even worry about it. It's less genetic as such, spanning back countless thousands of years when the Old Ones were exposed to raw magic and radiation and time stuff. What I can explain is basically - think Tokyo Ghoul. It's basically just like that. I might end up changing that in the future, but for now just go of that and you'll be fine.

Well... A Pike to the face might damage them a... Lot... XD