Ok, gonna throw my two cents into the ring...Not sure if this is what Chrissy had in mind but this is how I see it:
Aneurin is dead, what has taken his place is some kind of mishmash of all the elf kings, sort of a genetic memory that was unlocked by the spell Caoilfionn and Islwyn; so Anuerin is still in there but he is now a small part of the whole and from the sounds of it a very subservient part, he Called Val a Dy'nn and the true Aneurin never would have, that would be like Magus calling me or Kari a whore, never happen. Now this hot tub party might bring the old Aneurin to the for front but it will never be him, not really and she's willing to try but I think the influence of the kings of the past will never let him see her as more than a pet. No, sorry but what they had is as dead as her old lover.
As for Yorwrath, I think you are all underestimating him. His abrasive manner was his way of keeping people at bay. He loved a human woman deeply and his father took that away from him, made him watch her die a horrible death, as well watching his son die. I couldn't even imagine what that would be like and honestly hope I never have to find out, but I know someone who does know and I watched him go through something quite similar. Yorwrath is just trying to never get close enough to anyone, especially a human female, so he never has to feel that pain again. But his walls are cracking, he didn't want to have rough sex with Val, he wanted to make love with her like his brother did and that tells me that no matter how he rails against it he's falling in love with her. I see the old Yorwrath resurfacing, the one his brother said was kind and even happy and when Val sees what's under that cold exterior I think she'll re-evaluate him and the two of them may find comfort in each others arms, a comfort that will grow into a deep love...I'm a romantic
As for Islwyn and the unicorn, gonna have to go with Kari on this one, they die slowly and screaming.
So I see a future with Yorwrath and Val presiding over a house full of little half elf half human rug rats, maybe not a happily ever after, but a bitter sweet ending.