Council of Thieves
Tieflings in Cheliax:
Tieflings enjoy an unusual status in Cheliax, though perhaps “enjoy” is the wrong word. Chelish diabolists view tieflings as subordinate to humans. Tieflings are seen as lesser beings, born of human fallibility or devilish trickery.
Noble houses hide tiefling heirs away, ashamed of their very existence, or reluctantly allow them some control over the family business (usually if there is no other reliable heir available).
Because of this tarnished history, most tieflings in Cheliax carry around hatred and resentment in their hearts. Some strive for greatness as a way to prove their worth and show up those who failed to appreciate their talents.
Others embrace their heritage and become fiends in mortal form, running illegal operations, thieving, murdering, or worse.
Most fall somewhere between these extremes, struggling to find their path among the
Tieflings are listed in greater detail on the PFSRD. Feel free to customize your character as you see fit.