What's the Name of That Book??? discussion

Hi, I am new to the group and in need of some help.

I've been discussing dark fantasy horror books with a friend who likes more horror-esque books and I was discussing a particular book I read some years ago, at least four or five years back, while talking to her I searched google, goodreads and even searched the local library database (where I had picked up the book I'm referring to) and I could not find the book at all. I am half concerned that I had some strangely detailed fever dream as I cannot find this book for the life of me and so I am hoping you guys might be able to help.

Now, admittedly, I have forgotten a decent ammount of the book, I can't remember what the plot was precisely but I can remember some specific details about some things that occurred within the book, so I hope that someone here might recognize some of these details and point me to the correct book, if it exists and wasn't a strange fever dream I had! :D

The book was about dark elves, but the author called them ælves, I recall this perfectly as I was reading a goodread's review that someone wrote mocking the use of the spelling as doesn't change the pronunciation of the word, elf. The dark elves are lead by twins who cannot be looked upon, if anyone 'lesser' looks upon these twins they instantly die, as a result the twins, one male and female, are in a sexual relationship as no-one else can look at them. They have human slaves and I vaguely recall what can only be called a lobotomy. The elves were trying to 'manage' the rebellious workforce and their solution was to do something to the human brain to make the humans docile, and they do this to a large rebellious man. These dark elves also consider themselves the greatest artisans as they use bodily fluid, like blood, and body parts to make macabre artworks.

Our main character of the book has a long name that begins with C. He and his wife are a rarity among their kind because they practice monogamy, you see, this pair genuinely love each other and want no-one else. The women, when they have children, develop a strand of white hair, the more white hair, the more children that woman has had. C, is given a quest by his incestuous leaders, and told either he comes back successful or does not come back at all. In his journey he meets a human character, a woman from a tribe who wears the skin of their enemies. She leaves C and travels to C's home to murder his wife and adorn herself with his wife's skin, much to C's horror.

I think there was another character in the book, an 'artist' who poked his human slave's eyes, rendering her blind because he wanted to deny her the opportunity to look upon the 'beauty' of his work. And despite his abuse and torture of her, she still loves and adores him.

I wish I could give more detail, especially about the plot but I read this book years ago and disliked it, but my friend loves this genre and I hoped to recommend it to her, only I cannot find this book anywhere. Please help!

I didn't get much with "ælf"/"ælves" but I got more results with "aelf"/"aelves". Mostly RPG websites/pages but I found Duality by Stuart Richardson here: https://www.everand.com/book/50306649...