I don't think I'll go back to the Twiceborn being undead. The Shunned Ones are undead, but they are failures. The fact that are undead is why they are shunned. If anything, the Twiceborn might be magic beings.
About Hellraiser, the Cenobites have something in common with the Twiceborn, sure.
Feel free to make a ghoul nation. Interested to see what you come up with.
