The woman in the black robe was indifferent to this situation, but Sun Xingbiao was her employer. She had agreed to come to the barren land of the Cultivation World of Great Zhao not just for the money Sun Xingbiao offered, but because she was somewhat taken with him. Sun Xingbiao met her requirements for a dual cultivation partner and had subtly revealed similar intentions.
Once a woman is moved emotionally, she is willing to do unconventional things for the man she is interested in. The woman in the black robe decided to abandon her principles and accept this mission in Great Zhao, including protecting the safety of Marquis Ma, despite not caring for his power. She agreed to this only due to Sun Xingbiao's repeated requests. Otherwise, she would never have allowed Marquis Ma aboard her Spirit Vessel, let alone agree to protect his safety.