“Just because I can turn you to “stone” doesn’t mean you can be stone cold to me." Manuya Teoshi
The curse is a form of wild magic the manifests in a person giving them great power but over time changes them. It allows the affected one to look at someone and stop them in their tracks, or later on, turn people to stone. The cursed develop amazing beauty even when they grow snakes for hair.
How it came to be
As far as it is known it comes from the grand mother of Manuya Teoshi named Zihu Sitali. It came about when she caused uprisings and attacks against the upper tiers of the Yuan-ti castes. To stop Zihu, they cursed and exiled her to prevent her from coming back to gain power. They didn’t know what they had actually done.
Unique to the Mixture
What makes the bloodline special is that it grants great power and and unknown length of life to the user. The great power it gives is innate spell casting making those who are cursed a Sorcerer. Although the only reported case so far seems to skip over a generation every time a cursed has a child.