That much was clear when you made this response touting your greatness when presented with this great advice to a fairly similar situation. I've said multiple times that I have zero tolerance for allowing FR stuff in my eberron games, but that line is drawn after I take the time to point my players to all the "cool naughty word" in my world that might scratch their itch with a few tweaks to their concept. You might not have planned for an unsullied, but weapons proficiencies, skills useful for a potential owner to have an unsullied know , &magically altered bodies with eyes that can maybe see in the dark is pretty close to an elf.Well, the RL negotiation happened pretty much the way I laid it out in my OP.
The fault is on you the GM for not trying to redirect a poorly fitting idea towards some great fitting thing that does exist in your world by describing some of the awesome things about it & getting the player on board with one of the things you could have pointed to that would enhance your game with depth.