Custom Slaves For Sale -Only for the most powerful of Nobles

With the recent fall of the Demon King, the threat of looming Demons has been lessened. Would society me more accepting of Dark-kin?
I was thinking that a morally corrupted Coryani wizard could start making custom slaves, using the blood of demons to power a joining spell to meld a child born into slavery with an animal. These slaves would be specially designed to fill a role. (Making them Darl-kin). These specialty slaves would then be sold to Rich Nobles who would use these slaves not only for its designed task but use these as a status symbol.
Boy, Plus Bull to make a Minatare for Battle or heavy labour,
Girl with Rodent to make a subservient maid that won’t wake the house hold as she starts the morning fires.
Child with a Hound to be a cook in the kitchen because it would be able to prepare superior meals because of its advanced sense of smell.
Child with a colorful Bird to make a servant that looks exotic.
I think this is not something one would find in Canceri as hat is location is evil from necessity rather than from indulgence.
I think I would like to write an adventure about this occurrence, and how the PC would react to it, especially if the children were not born slaves but children stolen from peasants.

Opinions?