I've been wanting to this for the longest time, however, I couldn't make it work.
The D&D suppliment Lords of Darkness had a section that detailed the Daemonfey. Luckily, Wizards kept it online as well as a teaser to Lords of Darkness. http://www.wizards.com/default.asp?x=dnd/ex/20010112&pf=true
And here's Commie-pedias take on the Daemonfeyhttp://en.wikipedia.org/wiki/Daemonfey
Essentially, some Sun Elves covorted with some demons, and their offspring were "blessed" with the best of both worlds. Of course, shit happens, and the Daemonfey have deep-seeded hatred of elves. So, Sarya Dlardrageth decides to capture the "most beautiful" of the Elves and plans on using them in "breeding programs" as an act of Revenge and to bolster their ranks.
The idea I worked out was:
DM would act as Sarya Dlardrageth, either commanding other PC's, or partaking of them.
Several PC's would be Daemonfey, however, room would be made for Demons and Devils like Succubi and the like. Other PC's would be the enslaved Elves.
As the account implies, there would be a number of NC scenarios (i.e. rape). Now that I think about it, the book did predate Book of Vile Darkness....
Anyway, after some modification, I came up with this for the forums:
DM would act as Sarya Dlardrageth. However, the focus is on a set "Core" group of sorts.
This "core group" would be several handpicked Daemonfey, and several "sample" elves captured for "evaluation purposes." And the various "demons" summoned for the purposes of finding out which ones were the best.
I dunno know, it feels like something is missing....any advice? Or players that wanna try it out?